aGRO 2011 Biennial Conference BOOK OF ABSTRACTS

Transcription

UNIVERSITY OF NAIROBI
COLLEGE OF AGRICULTURE AND VETERINARY SCIENCES
FACULTY OF AGRICULTURE
aGRO 2011 Biennial Conference
The Inaugural Biennial Conference of the Faculty of Agriculture
‘OPTIMIZATION OF AGRICULTURAL VALUE CHAINS FOR SUSTAINABLE
DEVELOPMENT’
26th – 28th September 2011
BOOK OF ABSTRACTS
aGRO 2011 Biennial Conference © Copyright
No part of this publication may be reproduced, translated or transmitted in any form or by any
means without the prior written permission of the publisher. Information carried in each abstract
remains the responsibility of the author(s).
Published by:
aGRO 2011 Secretariat
Faculty of Agriculture, University of Nairobi
P.O Box 29053-00625
NAIROBI
aGRO 2011 Biennial Conference ACKNOWLEDGEMENT
We wish to acknowledge the commitment and hard work of the members of the organizing
committee and members of the Faculty of Agriculture who were co-opted to assist with the
organization of aGRO 2011 Biennial Conference.
We highly appreciate the academic staff of the Faculty of Agriculture who diligently reviewed
the abstracts to ensure a high quality publication.
Special thanks go to the following members of the Faculty of Agriculture who donated the seed
money from their research projects to initiate the planning of the conference:
Prof. A.Mwang’ombe
Prof. C.K.K. Gachene
Prof. P. M. Kimani
Prof. R. G. Wahome
Prof. N. Karanja
Dr. E.C.K.Ngugi
Prof. J. T. Njoka
Dr. J. Mburu
Prof. R. N. Kinuthia
We sincerely thank the National Council of Science and Technology and The Kenya Seed
Company both of whom are the main sponsors of the conference and the Twiga Chemicals for
additional financial support.
Above all, we thank all the presenters/authors for choosing aGRO 2011 as the platform to share
their research findings and showcase their products, thereby enabling us to host this great event.
aGRO 2011 Biennial Conference CONFERENCE COMMITTEES
Organizing Committee
Prof. Ratemo Michieka – Chairman
Dr. Jane Ambuko – Organizing Secretary
Prof. Nancy Karanja
Dr. Rose Nyikal
Dr. Safary Ariga
Dr. Kahiu Ngugi
Dr. George Ooko
Dr. Jane Wamatu
Mr. Calvince Ouko (Graduate student)
Technical Review/Editorial Committee
Prof. Nancy Karanja
Dr. Kahiu Ngugi
Dr. Jane Ambuko
Dr. Mary Mburu (Co-opted)
Catering and Hospitality
Dr. Mary Mburu (Co-opted)
Dr. Richard Nyankanga (Co-opted)
Prof. Nancy Karanja
Dr. Jane Ambuko
aGRO 2011 Biennial Conference Exhibitions and Posters
Dr. Safary Ariga
Dr. Jane Ambuko
Mr. David Karanja
Mr. S.K. Tirop
Logistics
Prof. Ratemo Michieka
Prof. Nancy Karanja
Dr. Jane Ambuko
Dr. Rose Nyikal
Dr. Safary Ariga
Transport and Security
Mr. Titus Magomere
Mr. Henry Kahe
Mr. David Karanja
Co-opted Graduate students
Susan Munialo
Lydia Nyambok
Maureen Waswa
Henry Mwaka
Elly Ouma
Penina Yumbya
Frankline Otiende
Josephat Mokaya
Emilly Injete
Clara Machog
Phillip Onyono
Clarice Munyambo
aGRO 2011 Biennial Conference PREFACE
aGRO 2011 is the inaugural biennial conference organized by the University of Nairobi’s
Faculty of Agriculture with the theme ‘Optimization of Agricultural Value Chains for
Sustainable Development’.
Many countries have applied science and technology based solutions to sustainably address
constraints to agricultural productivity, thereby realizing food and nutritional security. Extensive
agricultural research in Sub-Saharan Africa has generated applicable technological solutions to
low productivity, but these have not been optimally exploited. Poor linkages among agricultural
researchers and other stakeholders are partly to blame for ‘shelved’ technologies and innovations.
Therefore, aGRO 2011 aims to bridge this gap by bringing together researchers, extension
service providers, policy makers, producers, processers and traders in the agricultural sector with
diverse expertise and experiences. These stakeholders will share research findings and lessons
learnt from the successes and failures of previous technology transfer initiatives. The forum will
shed light on novel research and development approaches that will have a positive impact on
sustainable agricultural productivity and reduce inefficiencies in agricultural value chains. The
conference will have a 3-day program which will include scientific and technical sessions. There
will be plenary sessions with invited keynote speakers and break away sessions for the various
sub themes. A special plenary session ‘Genetically Modified Organisms – Myths and Facts’
brings together experts in Biotechnology from various sectors to discuss this ‘hot’ topic.
Posters and exhibitions will be displayed in the Exhibition/Poster gallery throughout the
conference period. There will also be a special poster session during which poster presenters will
discuss their presentations with participants.
We take this opportunity to welcome you to the aGRO 2011 Inaugural Biennial Conference of
the Faculty of Agriculture.
aGRO 2011 Biennial Conference CONTENT GUIDELINE
ORAL PRESENTATIONS
•
Sub theme 1: Environmental and Natural Resource Management…………………2
•
Sub theme 2: Food and Nutritional Security……………………………………....30
•
Subtheme 3: Agribusiness, Extension and Technology Transfer…………………92
•
Sub theme 4: Gender, Policy and Governance in Agriculture…………………..124
POSTER PRESENTATIONS
•
Sub theme 1: Environmental and Natural Resource Management……………...131
•
Sub theme 2: Food and Nutritional Security…………………………………….134
•
Subtheme 3: Agribusiness, Extension and Technology Transfer…….…………181
GUIDELINES TO AUTHORS (EAAFJ) ………………………………………………….182
aGRO 2011 Biennial Conference ORAL PRESENTATIONS
aGRO 2011 Biennial Conference SUBTHEME 1
Environment and Natural Resource Management
aGRO 2011 Biennial Conference L1001. EFFECT OF SEDIMENT LOADING FROM THE MUSEUM HILL ROUNDABOUT RECONSTRUCTION ON BENTHOS OF NAIROBI RIVER
Abdalla Felix
University of Nairobi, School of Biological Sciences
Corresponding author: [email protected]
Abstract
In determining the effect of sediment loading resulting from the museum hill round-about
reconstruction on benthos of Nairobi River, a study was carried out with the objective of
determining the abundance of macro and meio benthos in relation to sediment loading at the site
of study. The method used for this experiment involved determination of sediment loading at
various sampling sites; in this case the total suspended solids were analyzed to determine the
sediment loading in two streams (Kirichwa 1 and Kirichwa 2) which cover the study site. The
analysis of benthos was done by scooping the bottom substrate from the river at various
sampling points. The samples were passed through sieves of different sizes depending on the
type of analysis (Meio or Macro) and processed for observation under compound microscope
and the number of benthos present counted. A similar procedure was done on samples obtained
from a selected control site. This was a seasonal stream at the university of Nairobi sports ground
that had a variety of benthos and was found to be suitable as a control. Analysis of sediment
loading was done by filtering water collected from the sampling points with a suction pump with
chlorophyll A filtration filter papers were dried in an oven at 78oC and stored in desiccators for
30 minutes then weighed. After filtration of the sampled river water the filter papers with trapped
substrate were dried in an oven at 78oC for 48 hours and then weighed. The wet mass and dry
mass of the samples was obtained and was divided by the respective volume of water filtered to
determine the sediment load in g/ml. The sediment load and abundance of benthos from the
respective sampling sites were compared and a relationship was established. The key results
showed a general variation in diversity, type and abundance of benthos with increase in sediment
loading. In conclusion, it was observed that despite the fact that sediment loading may not be the
only factor affecting the abundance of benthos along the river gradient, at the sampling points
there was a general decrease in benthos with sediment loading.
Key words: Nairobi River, Meiobenthos, Macrobenthos, Sediment loading.
aGRO 2011 Biennial Conference L1003. SOIL MACROFAUNA IN SOILS UNDER DIFFERING LEVELS OF
DISTURBANCE AND LAND USE INTENSITY IN KAKAMEGA DISTRICT, KENYA
Ayuke, F.O.1*, Karanja, N.K.1 and Awiti, A.2
1
Department of Land Resource Management and Agricultural Technology, University of
Nairobi, P.O Box 30197 Nairobi, Kenya
2
Faculty of Arts and Sciences, Aga Khan University, P.O Box 30270, Nairobi, Kenya
*
Abstract
This paper presents data on soil macrofauna diversity and abundance in parts of Kakamega
Forest Reserve, the last remnants of the once great equatorial forest that stretched from West
Africa through the Congo Basin and into East Africa. The habitats studied included four land
use systems (primary forest, secondary forest, fallow and arable) representing a land use
intensity gradient from primary forest to arable fields which had been under cultivation for
periods ranging from 1 to 100 years. The farms were grouped into three clusters which
comprised of: arable1 (1-10 years), arable 2 (20-40 years) and arable 3 (>40 years). Forty seven
genera/species of soil macrofauna were recorded out of which 15 species were unique to the
forest soils. Sum of all canonical eigenvalues revealed that sampling time within season
explained 6% of the variation in species. Soil parameters explained 9%, whereas land use
intensity explained 17% of the total variation observed in macrofauna abundance. Three percent
loss of species occurred due to forest disturbance while continuous cultivation had substantial
effect on macrofauna diversity. Continuous cultivation for 10 and 40 years resulted in 16% and
over 50% loss in soil biodiversity, respectively. Thus conversion of forests to arable lands
coupled by low inputs resulted in decline in its soil biological attributes. These changes were
associated with management practices that consequently resulted in the destruction of nesting
habitats, modification of soil microclimate within these habitats and removal of substrate, low
diversity and availability of food sources for the associated macrofauna groups. At the process
level, these changes could result in a fundamental shift in ecosystem function related to soil
organic carbon dynamics, nutrient cycling and soil physical properties. Thus there is a need to
establish how ecosystem functioning is influenced by soil biota and to assess whether the balance
is negative or positive at farm level.
Key words: Community structure, diversity, abundance, land use intensity, soil fauna
aGRO 2011 Biennial Conference L1006. INFLUENCE OF SOIL ORGANIC MATTER QUALITY ON TEMPERATURE
SENSITIVITY OF DECOMPOSITION
1
Basweti C., 1Nancy Karanja* and 2L. Verchot.
1
Department of Land Resources Management and Agricultural Technology, University of
Nairobi, P.O. Box 30193, Nairobi, Kenya,
2
Centre for International Forestry Research (CIFOR), P.O. Box 0113 BOCBD, Bogor 16000,
Indonesia.
Abstract
Temperature sensitivity of decomposition is key in determining terrestrial carbon responses to
global change though differences between recalcitrant and labile carbon pools have not been
demonstrated. The objective of the study was to evaluate the effect of organic matter quality on
temperature sensitivity of soil organic matter (SOM) decomposition under three temperature
levels and two soil moisture levels. A chronosequence approach was used to obtain organic
matter with varying quality attributes across a cultivation chronosequence in which land-use
history ranged from a recently converted primary forest to 80 years of continuous cropping in the
highlands of Western Kenya. From each conversion time, soil was sampled to a 10 cm depth in
three replicates in January 2009 and incubated for carbon dioxide (CO2) evolution at three
temperature levels (10oC, 25oC and 33oC) and two soil water content levels (50% and 100%
water holding capacity - WHC). Total carbon (C) and nitrogen (N) were analyzed using dry
combustion method while SOM quality was characterized using Mid-Infrared spectroscopy.C
and N loss in 80 years of cultivation ranged between 60 and 70% with decomposition rates
increasing (R2 = 0.99; P<0.001) with temperature. Rates of CO2 emissions were highest at 50%
WHC. Recalcitrant carbon pools increased with cultivation period and were found to influence
(P<0.05) temperature sensitivity. Sensitivity was similar at 100% WHC for forest and cultivated
soils. Study indicates that SOM quality affects sensitivity of soil organic matter decomposition to
temperature. Incorporation of these factors into carbon cycle models will help in predicting effect
of climate change on SOC storage. It will also help in managing SOC in various landscapes
through improved land management that mitigate C release.
Keywords: decomposition, temperature sensitivity, water, soil organic matter
aGRO 2011 Biennial Conference L1004. WILD EDIBLE PLANTS: A POTENTIAL TO ENHANCE
AGROBIODIVERSITY AND PEOPLE’S RESILIENCE TO CHANGING ECOSYSTEM
1
Feyssa Debela Hunde, 1Jesse T. Njoka, 2Zemede Asfaw, 1M.M.Nyangito
1
Department of Land Resources & Agricultural Technology, College of Agriculture & Veterinary
Sciences, University of Nairobi, Kenya
2
Plant Biology & Biodiversity Management Programme Unit, College of Natural Sciences, Addis
Ababa University, Ethiopia
Abstract
Wild edible plants are accessible, available and cheaper to diversify household diet in drylands.
However, the diversity and resource base are not properly documented to inform policy makers for
proper utilization. Therefore, a study was conducted in the semiarid part of east Shewa in Fantalle
(transhumance pastoralists) and Boosat (settled farmers) districts to determine the diversity,
abundance and densities of wild edible plants. Species data was collected by field inspection,
participatory observations with recording of the dominant vegetation (shrubs and trees) and WEPs
of along six transects. Ninety plant species were identified as a major component of vegetation of
the study area in which 40 wild edible plants are distributed. The wild edible plants were identified
by interview, focus group discussions and through key informants’ field walks. Shannon-Weiner
diversity indice measured for the species diversity and evenness of species distribution across six
study sites showed no significant difference (P>0.05) between the study sites. Whithaker beta (βw)
diversity calculated for species composition turn-over across study sites is not significantly different
(P>0.05). Jaccard’s coefficient similarity in number of species used between transhumance and
settled farmers districts was 66.67%. The results indicated that the districts are potentially similar in
terms of plant biodiversity. However, mean values of abundance and densities vary across land
uses. The transhumance land use has better abundances and densities for some species of wild
edible plants. Lantana camara, Ziziphus spina-christi and Acacia senegal ranked 1st to 3rd
respectively in abundance and densities. Being in the arid region within a fragile ecosystem, the
study area east Shewa cannot be free from climate variability and change consequences. Hence, the
resilience of human livelihoods could be enhanced by integrating conservation and sustainable use
of wild edible plants in dryland agro-biodiversity.
Keywords: changing ecosystem, resilience, diversity indices, Jaccard’s, agro-biodiversity.
aGRO 2011 Biennial Conference L1041. THE DIVERSITY OF MEDICINAL PLANTS AT THE BOTANICAL GARDEN
IN UNIVERSITY OF NAIROBI (UPPER KABETE CAMPUS)
1
Gathumbi P. K., 2Amenya H. Z., 3Ochung’ A. O. , 3Musembi J.K. , 1Gachoka, J.M., Ngugi,
1
R.K. , and 4Kariuki, S.K.
1
Department of Veterinary Pathology, Microbiology and Parasitology, University of Nairobi.,
Kenya.
2
Department of Public Health, Pharmacology and Toxicology, University of Nairobi, Kenya.
3
Nairobi, Kenya.
4
Egerton University, Department of Biological Sciences, P.O. Box Private Bag Njoro
Abstract
A botanical garden comprising different species of medicinal plants was established at the
University of Nairobi’s College of Agriculture and Veterinary Sciences in April 2009. Prior to
the establishment of the garden, an inventory of species and genus of plants on the site was
recorded using the line transect method. Photographs and voucher specimens were also taken.
The area was then cleared and different species of medicinal plants were planted. Before it was
cleared, the site had a total of 87 plant species belonging to 74 genera and 36 families, which
comprised of 41.4% herbs, 18.4% trees, 25.3% shrubs and 13.8% grasses. The most abundant
families were Papilionaceae (9.2%), Compositae (8.1%), Acanthaceae (5.8%), Malvaceae
(4.6%), Rubiaceae (4.6%); and Verbenaceae, Caesalpiniaceae and Labiatae (3.5% each). The
garden has 497 medicinal plants consisting of 47 species and 26 families. Most of species and
genera of plants in the garden, are in Rutaceae (15%), Euphorbiaceae (8.7%), Apocynaceae,
Caesalpinaceae, Mimosaceae, and Papilionaceae, 6.5% each, respectively. This botanical
garden is currently used as a demonstration site for best practices in exsitu propagation of rare
medicinal plant species. The resultant species, genera and families and their medicinal potential
are presented.
aGRO 2011 Biennial Conference L1005. HEAVY METAL AND PESTICIDE RESIDUE CONTAMINATION IN LEAFY
VEGETABLES IN PERI-URBAN FARMS OF NAIROBI, KENYA
Karanja, N.K1., Njenga, M2., Mutua, G.K1., Carl-Johan Lagerkvist3, E. Kutto1, and
Okello, J.J1
1
University of Nairobi, College of and Agriculture and Veterinary Medicine, P. O. Box, 3019700100, Nairobi.
2
Urban Harvest-CIP.
3
Uppsala University, Department of Agricultural Sciences, Sweden
Abstract
Assessment of heavy metal contaminants, nitrate and pesticide residues was done on kale
(Brassica olaracea var. olecephala), a leafy vegetable grown by farmers in peri-urban sites of
Wangige, Athi River and Ngong in Nairobi, Kenya in both wet and dry seasons. Kale leaves
were picked from lower, middle and upper part of each plant randomly selected in a zigzag
pattern in each plot per farm alongside soil samples to a depth of 15 cm from the same plots.
Irrigation water samples used by the farmers on the vegetable crop and manures from Wangige
site were also collected. Concentrations of Arsenic (As) in kale leaves obtained from Wangige,
Ngong and Athi River were 17.72, 10.68 and 8.15 mg/kg, respectively. Wangige vegetables
exceeded the acceptable critical levels of 15mg/kg for As in leafy vegetables. The concentration
of Pb in kale ranged from 0.39 mg/kg to 3.06 mg/kg for Wangige and Athi river, respectively,
translating to a dietary Pb intake of 0.078mg/kg to 0.612mg/kg in adults. Kale leaf tissues from
Wangige and Ngong had levels above the recommended maximum crop concentration of 0.2
mg/l. Nitrate content in kale from the three locations were within acceptable daily intakes. In a
frequency of 1/5 farms, diazinon, cypermethrin, prophenos, biternol exceeded the maximum
residue levels in both wet and dry seasons. These findings indicate that safety of leafy
vegetables produced in the peri-urban areas of Nairobi is likely to be compromised from the
farms through use of untreated /low quality irrigation water and manure and improper pesticide
use. The policy implication of the findings is to promote awareness among growers of the need
to apply safe water and pesticides, especially because some of the growers sampled in this study
supplied supermarkets which are generally perceived by consumers to retail safe foodstuffs.
Key words: peri-urban, leafy vegetables, heavy metal concentrations, pesticide residue, food
safety.
aGRO 2011 Biennial Conference L1007. NEMATODE DIVERSITY AND THE EFFECTS OF BACILLUS AND
RHIZOBIUM ON THE MANAGEMENT OF PLANT PARASITIC NEMATODES IN
COMMON BEAN
*1
Karanja, N.. Mutua, G.K1, Ayuke, F.1, Ndukhu2, H., and Kimenju, J.W1
1
Faculty of Agriculture, University of Nairobi, P.O Box 30197 Nairobi, Kenya
2
Ministry of Agriculture, P.O Box 9-2025 Sosiot, Kericho, Kenya
Abstract
Nematode losses in vegetable crops have contributed to significant loss in yield reducing
food security. Assessment of the potential of dual inoculation of Bacillus subtilis and
Rhizobium leguminosarum biovar phaseoli strain USDA 2674 on plant parasitic
nematodes in common bean was carried out on farmers’ fields which were at varying
cultivation period since conversion from forest as follows; 1-10, 10-20, 20-40 and >40 years.
Bean seeds of variety Rose Coco, were treated with three B. subtilis isolates namely K158,
K194 and K263 singly or in combination with Rhizobium and then planted in nematode
infested fields. Plant parasitic nematodes in the genera Meloidogyne, Pratylenchus and
Scutelonema were dominant. Nematode diversity assessed by Shannon (4.10-1.70), Simpson’s
(5.23-3.74), Trophic (2.84-1.26) and Maturity indices (3.92-2.31) declined with increased length
of cultivation since conversion from forest. Plant parasitic index was 63% higher in the
cultivated farms than in the control plots. The dual innoculant enhanced nodulation variably
depending on the length of cultivation and increased bean yields compared to the control.
Bacillus subtilis isolates K194, K158 and K263 suppressed plant parasitic nematodes by 42, 36
and 28%, respectively. The potential of dual inoculation of Bacillus and Rhizobium in addressing
nematode and soil fertility challenges was demonstrated in this study.
Key words: Bacillus; diversity; nematodes; nodulation; Rhizobium
aGRO 2011 Biennial Conference L1008. ASSESSMENT OF LAND USE AND LAND COVER CHANGES IN RIVER
GUCHA CATCHMENT, KENYA
KATHUMO, V.M. 1*,
GACHENE, C.K.K.1,
GICHERU, P.T.2,
KARIUKI, P. C.3
1
Department of Land Resource Management and Agricultural Technology (LARMAT),
University of Nairobi. P.O. Box 29053-00625, Nairobi, Kenya.
2
Kenya Agricultural Research Institute, Kabete. P.O. Box 14733, Nairobi, Kenya.
3
Department of Geosciences, South Eastern University College. P.O. Box 170-90200, Kitui
*
Abstract
Land use and land cover changes are important factors in the hydrological cycle and the spatialtemporal variations in the distribution of natural resources. The objective of this study was to
assess trend in land use and land cover change in River Gucha Catchment. LANDSAT MSS,
ETM and ETM+ images of 1976, 1993 and 2010 respectively of the study area were classified
and percentage changes of land use and land cover types determined for the period between
1976-1993 and 1993-2010. Agriculture, which is the main land use in the catchment, covered
about 92% of the catchment’s area. Forest covered about 4%, while settlement covered the
remaining 4%. Forest cover decreased by 62.94 and 68.49%, agricultural land increased by
30.36 and 7.53% and residential area increased by 7.35 and 32.89% of the original area for the
period between 1976-1993 and 1993-2010 respectively. The reduction of forest cover could be
attributed to clearing of forests to give room for cultivation and settlement. This reduction in
forest cover and expansion of agricultural and settlement area could result to increased peak
flows, soil erosion and reduction in base flow of the River. Understanding the trend in land
use/cover types will enable planners to formulate policies towards minimizing the undesirable
effects of future land use/cover changes on natural resources.
Key words; land use change, land cover change, catchment area.
aGRO 2011 Biennial Conference L1010. IMPACT OF LAND USE INTENSITY ON SELECTED SOIL ORGANISMS IN
TAITA AND EMBU BENCHMARK SITES, KENYA
1
Kimenju J.W., 1P.M. Wachira, 1N.K. Karanja, 1S.A. Okoth, 2J.P.H. Kahindi, 3J.M Jefwa,
1
G.N Nyamasyo, 4E. Muya, 1B. Mutsotso, 3M. Gikungu, 3M. Kibberenge, and 5H. Roimen
1
University of Nairobi, P. O. Box 30197-00100, Nairobi, Kenya. 2United States International
University, Nairobi, P. O. Box 14634 - 00800, Nairobi, Kenya. 3The National Museums of Kenya
4
P.O Box 45166, -00100, Nairobi, Kenya. Kenya Agricultural Research Institute, P.O. Box
5
14733, -00100, Nairobi, Kenya. Department of Resource Surveys and Remote Sensing, P.O.
Box 47146, -00100, Nairobi
Abstract
Land use intensification leads to soil degradation and consequently to loss of biodiversity and
more specifically to soil biodiversity. A study was undertaken to assess the effect of land use
change on selected soil organisms at Embu and Taita Taveta benchmark sites in Kenya. Soil
samples were collected from geo-referenced points located in natural forest, plantation forest,
tea, coffee, napier grass, agro-forestry, fallow, maize/beans intercrop and land under horticultural
crop production. The soil organisms were grouped into three main categories based on their
morphology and sizes as follows; microbes, mesofauna and macrofauna. A general decline in
diversity and abundance of beneficial microbes was observed with increase in land use intensity.
Richness and abundance of Trichoderma was highest and lowest at the napier grass and
coffeebenchmark sites, respectively. Land use intensification had no significant effect on
arbuscular mycorrhizal fungi (AMF) populations and their diversity. Results also confirm that
land use has a significant effect on the diversity of rhizobia. It was also observed that the
frequency of isolating nematode destroying fungi (NDFs) increased with increase in land use
intensity. An increase in abundance of plant pathogenic microbes was associated with intensity
of land use where the abundance of Fusarium and Pythium spp.was significatlty (P<0.05)
affected by land use. The ratios of free-living to plant parasitic nematodes were 5.18 and 0.54 in
the natural forest and annual crop production systems, respectively. Similarly, the abundance and
diversity of collembollas decreased with increase in land use intensity. This study confirmed the
hypothesis that land use intensification significantly led to loss in soil biodiversity which may
account for the decline in soil quality and productivity.
Key words: Soil
intensification.
biodiversity,
microorganisms,
mesofauna,
macrofauna,
diversity,
aGRO 2011 Biennial Conference L1011. MANAGEMENT OF PLANT PARASITIC NEMATODES USING NONCHEMICAL STRATEGIES UNDER INTENSIVE CARNATION PRODUCTION
SYSTEMS
1
*Kimenju J.W., 1Lang’at, J.K., 1Wachira, P.M, .2Otieno, W., and 1Mutua G. K.
1
University of Nairobi, P.O. Box 30197-00100 Nairobi, Kenya
2
Kenya Plant Health Inspectorate Service, P.O. Box 49592 – 00100, Nairobi, Kenya
Abstract
This study was carried out with the aim of developing sustainable approaches for management of
phyto-nematodes affecting carnations. Selected organic substrates namely; sugarcane bagasse,
tea, assorted flower composts and molasses, nematophagous fungus Paecilomyces lilacinus (PL
plus®) and neem (Achook®) were evaluated against a standard chemical nematicide, fenamiphos
(Nemacur®), and an untreated control. The experiments were carried out under greenhouse
conditions. Soil samples were collected before application/planting and at 90 and 180 days after
treatment. Parasitic nematodes belonging to 16 genera were detected in plots where carnations
were grown as monoculture crop for several years. The most predominant nematodes detected
were in the genera Scutellonema, Meloidogyne and Helicotylenchus, with 100 and 82%
frequencies of occurrence, respectively. Incooporation of the treatments reduced the numbers of
plant parasitic nematodes, except Helicotylenchus, Criconema and Longidorus genera. Galling
due to root-knot nematode was reduced by 53%, in plots treated with sugarcane bagasse and,
69% by the neem product. This study established that application of organic substrates, neem and
P. lilacinus were suppressive to plant parasitic nematodes. The materials could be recommended
for use in sustainable carnation production systems.
Key words: Dianthus caryophyllus, Meloidogyne spp., neem, organic substrates and
Paecilomyces lilacinus.
aGRO 2011 Biennial Conference L1012. RESTORATION OF NATURAL REGULATORY MECHANISMS OF PLANT
PARASITIC NEMATODES IN INTENSIVELY CULTIVATED LAND
1
1
*Wachira, P.M., Kimenju J.W., Okoth S. and Mibey, R.K.
University of Nairobi, P.O. Box 30197-00100 Nairobi, Kenya
* Corresponding author: [email protected]
Abstract
This study was undertaken to determine the effect of land use on nematode destroying fungi and
to identify soil fertility management practices that could be adopted to restore natural regulation
of plant parasitic nematodes. Soil samples were collected from land under forest, shrub, napier,
maize/bean, and vegetable crops in Taita Taveta District. Nematode destroying fungi, which are
natural enemies of plant parasitic nematodes, were isolated from the soil using the soil sprinkle
technique. Nematodes were extracted from soil and identified to the genus level. Greenhouse and
field experiments were conducted to evaluate the effect of cow manure, chicken manure and
their combinations on nematode destroying fungi, nematode community and growth of tomato
(Solanum lycopersicum L.). The frequency of occurrence of nematode destroying was
significantly affected by land use. The diversity index of nematode destroying fungi was highest
in land under horticultural cultivation followed by maize bean, napier, shrub and forest in that
descending order. Numbers of parasitic nematodes were higher in the intensively cultivated land
under crop cultivation compared to the less disturbed soil in the forest. Application of organic
amendments resulted in significant (P≤ 0.05) increase in occurrence of nematode destroying
fungi. The nematode destroying fungi occurred at frequencies of 50, 29.4, 17.6 and 2.9% in soil
amended with chicken manure, cow/chicken combination, cow manures and the control,
respectively. There was a 225, 96 and 62% increase in bacterial feeding nematodes and 391, 96
and 74% increase in fungal feeding nematodes in soil amended with chicken manure alone,
combination of chicken and cow manure. Addition of organic amendments caused an increase in
natural regulatory mechanisms which led to a decline of plant parasitic nematodes.
Key words: Bio-control, diversity, evenness, organic amendments, plant parasitic nematodes.
aGRO 2011 Biennial Conference L1013. EFFECT OF ADVERSE WEATHER CONDITIONS AND DISEASE ON
GROUNDNUT PRODUCTIVITY
1*
Kinama J. M., 2P.K. Runanu and 1M.W.K Mburu
1
Department of Plant Science and Crop Protection, University of Nairobi, PO Box 2953-00625,
Kabete, Kenya
2
*
Institute For Meteorological Training and Research, PO Box 30259-00100, Nairobi, Kenya
Corresponding author E-mail: [email protected]
Abstract
Groundnut (Arachis hypogea) is an important food, feed and cash crop in Eastern Africa but its
productivity is reduced by a wide range of temperature, humidity, and soil – water deficits
coupled with various diseases among them groundnut rosette virus disease, rust and aflatoxin
infection of the grain. Delays in the onset of the rainy season reduce the length of the growing
period which may result in lower yields. Variety-based tolerance to diseases and drought is a
cheap and sustainable way of increasing productivity for smallholder farmers who are the
predominant producers. Trials on groundnut varieties were conducted at Alupe and Kibos in
western Kenya. The objective of the study was to investigate the risk of seed and grain loses in
response to rainfall characteristics during the growing period in Western Kenya region. The
treatments were planting time, groundnut varieties and fertilizer treatments. The experimental
design was randomised complete block design (RCBD). Yield data was analyzed was subjected
to analysis of variance (ANOVA) The effect of rainfall distribution on groundnut seed yield on
decadal basis are discussed. Seed yield varied significantly among varieties but was not
infleuenced by fertilizer. Late planted groundnuts were highly affected by pests and diseases,
especially leaf rust and rosette, which contributed to low yields. High rainfall during harvesting
period led to increased grain rot, especially of the early maturing varieties. This calls for proper
timing of planting and harvesting of the groundnut crop. When the same cultivars of groundnuts
were grown under a wide range of environmental conditions, temperature and irradiance played a
major role in determining crop duration and partitioning of dry matter.
Key words: Adverse weather, disease, groundnuts, yield
aGRO 2011 Biennial Conference L1015. TILLAGE AND CROPPING SYSTEMS: EFFECTS ON SOIL MOISTURE AND
SORGHUM [SORGHUM BICOLOR (L)] YIELDS IN MAKUENI COUNTY, KENYA
Kitinya K. T., Onwonga, R.N., Mbuvi J. P. and G. Kironchi.
University of Nairobi, Department of Land Resource Management and Agricultural Technology,
P.O. Box 29053 – 00625 Nairobi
Abstract
A study to determine the effects of tillage and cropping systems on; soil surface roughness,
moisture storage and sorghum, and cowpea yield was conducted in the semi-arid Makueni
County, Kenya during the long (LRS) and short rains seasons (SRS) of 2010 and 2011. Three
tillage systems; tied-ridging (TR), oxen-plough (OP) and sub-soiling and ripping (SR) and, three
cropping systems; sole sorghum with and without manure application, sorghum-cowpea rotation
and sorghum/cowpea intercropping, were investigated. Surface roughness recorded immediately
after tillage was 75, 30 and 25% for TR, SR and OP, respectively. Moisture content below the
60 cm soil depth varied significantly (p<0.05) in the tillage-cropping system and cropping
season. Plots where manure was applied exhibited higher moisture content irrespective of tillage
or cropping system. Maximum and minimum sorghum grain yields of 1.96 and 0.36 t ha-1 were
achieved under TR and OP during the SRS and LRS, respectively. Differences in sorghum grain
yield with and without manure application were 78%, 57% and 24% and 28, 43% and 48% under
TR, OP and SR during the SRS and LRS respectively. Intercropping significantly reduced
(>50%) in cowpea (OP and SR) and sorghum (OP) yields during the SRS. In the LRS reductions
were minimal (<25%) across the tillage systems of both crops. The SRS favoured sorghum
production whereas cowpea performed better in the LRS. TR showed the least reduction in
yields across cropping systems. The TR systems could be boosted by manure application and
thus support sustainable production of sorghum in the semi-arid areas.
Key words; Crop rotation; cowpea; intercropping; crop rotation; soil surface roughness
aGRO 2011 Biennial Conference L1039. TURNING ADVERSITY INTO OPPORTUNITY: CAN PIGEONPEA DO IT?
Kwena, K.M1, 2, Karanja, N2, Gachene, C.C.K2, Esilaba, A.O3 and Vanlauwe, B4
1, 2
KARI-Katumani Research Centre, P.O. Box 340-90100, Machakos
2
University of Nairobi, Dept. of LARMAT, P.O. Box 29053-00625, Kangemi, Nairobi
3
Kenya Agricultural Research Institute, P.O. Box 57811-00200, City Square, Nairobi
4
TSBF- CIAT, P.O. Box 30677, Nairobi
Corresponding author : [email protected]
Abstract
Arid and semi-arid lands account for over 80% of Kenya’s landmass and support about 35-% of
her population. About 65-% of the inhabitants live below the poverty line. Several workers have
described the situation currently evident in these regions as a “poverty trap”, in which the highly
subsistence population living on degraded soils receives low income, afford low or no farm
inputs, and consequently get low crop yields. Studies indicate that pigeonpea could reverse this
trend. It ameliorates soils and boosts cereal yields tremendously. Locally, however, little has
been done to quantify these benefits. This study therefore sought to: (1) quantify the amount of
N, P and C accumulated by the different components of maize-pigeonpea intercropping systems
and its effect on soil C, N, P and exchangeable bases, and (2) assess the effect of pigeonpea
cropping systems and residue management on soil aggregation and soil water content. The study
was conducted at Katumani Research Centre for three seasons. Intercropping cereals with short
duration pigeonpea varieties depressed both pigeonpea grain and N yield. Cropping systems also
influenced accumulation of P in yield components of maize and pigeonpea. However, there were
no major changes in soil C, N and P. Soil macro- and micro-aggregates were affected by
cultivation and cropping systems. Cultivation reduced macro-aggregation but increased microaggregation. Soil water content increased across cropping systems with increase in residue
application rate. Thus, pigeonpea cropping systems have the potential to enrich or deplete the
soil, depending on the management.
Key words: Arid and semi-arid lands; pigeonpea; soil amelioration
aGRO 2011 Biennial Conference L1016. EFFECTS OF SOIL FERTILITY MANAGEMENT PRACTICES ON SOIL
AGGREGATION, CARBON AND NITROGEN DYNAMICS
Lelei, D.K.a*, Karanja, N.K.a, Ayuke, F.O.a, Kibunja, C.N.b, Vanlauwe, Bc
a*
Department of Land Resource Management and Agriculture Technology, University of
Nairobi, P.O.Box 30197-00100, Nairobi Kenya
b
Kenya Agricultural Research Institute, NARL-KARI, P.O. Box 14733-00800, Nairobi, Kenya
c
Tropical Soil Biology and Fertility (TSBF) Institute of CIAT, P.O. Box 30677-00100, Nairobi,
Kenya
*
Corresponding author Email: [email protected]
Abstract
Poor resource farmers cultivate steep slopes without soil conservation measures and apply
insufficient plant nutrients thus degrading the soils. Use of organic and inorganic sources of
nutrients is one of the approaches being advocated to farmers as a way of improving soil health
and increasing crop production. A study was conducted from a 31 year-old long-term trial at
Kabete, Central Kenya to investigate the effect of inorganic and organic inputs (maize stover and
farmyard manure) on soil aggregates, carbon, and nitrogen in a humic nitisol soil under annual
maize-bean crop rotation. The treatments for this study were: i) Inorganic fertilizer; ii) Farmyard
manure plus or minus inorganic fertilizer; iii) Maize stover plus or minus inorganic fertilizer and
iv) control (no inputs applied). The treatments were replicated three times in a randomized
complete block design. Soil samples were collected and subjected to wet sieving and
fractionation analyses to assess for water stable aggregates. Carbon and total nitrogen were
measured in all aggregate fractions and whole soil. Data collected were subjected to analysis of
variance. The results showed significant increase in large and small macroaggregates in 0-15 cm
and 15-30 cm depths under manure plus inorganic fertilizer treatment. Also, there was significant
increase in mean weight diameter of soil aggregates, soil organic carbon and total nitrogen in
macroaggregates and microaggregates, in treatment with farmyard manure plus inorganic
fertilizer. Long-term use of manure plus inorganic fertilizer improved the stability of the
macroaggregates and increased mean weight diameter in both 0-15 cm and 15-30 cm depths.
Thus integration of farmyard manures and inorganic fertilizers would result in buildup of soil
organic matter in the long-term, thus contributing to carbon sequestration in soils.
Key words: Carbon; Nitrogen Soil aggregate fractions.
aGRO 2011 Biennial Conference L1017. EFFECTS OF ORGANIC BIOMASSES ON COMPOST QUALITY, SOIL
HEALTH AND MAIZE PERFOMANCE
Mbau, S. K.1*, Ayuke, F.O. 1, Karanja, N. K.1
1
Nairobi, P. O. Box 29053-00625, Nairobi.
*
Corresponding author: [email protected] or [email protected]
Abstract
A study was conducted in Buyangu and Ivakale villages, Kakamega over three seasons from
March 2010 to August 2011 to evaluate the potential of six locally available organic biomass
sources namely; cow manure, maize stover, Tithonia diversifolia, sugarcane straw, bagasse and
filtermud for compost production and effect on soil quality, soil fauna diversity and on maize
yields. There was a total of eight treatments namely six composts made from the organic
biomass, a fertilizer treatment and a no-input control; replicated four times in randomized
complete block design. Soil samples were analyzed for chemical and biological parameters.
Earthworms were collected using monoliths while nematodes were sampled and extracted using
steel core samplers and Baerman pan techniques, respectively. Data obtained was subjected to
analysis of variance while treatment differences were compared using least significant
difference. There was no significant difference in chemical characteristics of composts prepared.
However, compost amendments had significant (P<0.001) effect on soil chemical properties.
Soils’ total N, organic C and extractable P were significantly higher in composts amended soils
than in control. On average, C and N increased by 90% and 21% respectively but P decreased by
2% in compost treatments while control had 37% increase in C but a 15% and 40% decrease in N
and P, respectively. Fertilizer treated soils recorded increase in all the three elements; 92, 26 and
81% in C, N and P, respectively. Earthworm abundance and biomasses were significantly higher
in compost treatments (38 individuals m-1 and 1.2 g m-1) than in fertilizer and control treatments
(10 individuals m-1 and 0.3 g m-1). Generally, plant-parasitic nematodes decreased with addition
of composts, whereas bacteria-feeding nematodes increased with application of composts. Maize
yields averaged over the three seasons were significantly highest in fertilizer treatments (4.4 t ha1
), followed by composts (2.8 t ha-1) and lowest in controls (1.4 t ha-1). Results demonstrate the
potential of composts to improve fertility and maize productivity.
Key words: composts, earthworms, nematodes, nitrogen, organic carbon, yield.
aGRO 2011 Biennial Conference L1018. IMPACT OF CLIMATE CHANGE ON ANIMAL PRODUCTION IN KENYA:
A REVIEW
Paul N. Mbugua
Department of Animal Production, University of Nairobi
Corresponding Author: [email protected]
Abstract
By 1995, over 2,500 scientists came to the conclusion that greenhouse gases emanating from
human activities had influenced global climate. Since mid 1990s, it has been noticed that greater
or fewer extreme weather events have been occurring in various parts of the world such as
droughts and floods partly due anthropogenic global warming, which has profound effect on
agricultural production. The effect of climate change on animal production includes: (i)
availability of feed; (ii) quality of feed; (iii) change in plant species forming the grazing sward
and, (iv) animals becoming heat stressed which in turn affects production. It has been estimated
that domestic livestock, rice farming, natural gas, petroleum processing and use, coal mining,
biomass burning, landfills, livestock manure and wastewater treatment emit 350 million metric
tons of greenhouse gases in a year with domestic livestock estimated to account for 23% of these
emissions. The effect of climate change not only affects the productivity of livestock but also the
livelihoods of the people, which is more pronounced in the arid and semi-arid lands of Kenya
than in other areas in country.
Key words: Climate change, Livestock production, Kenya,
aGRO 2011 Biennial Conference L1021. RAIN WATER HARVESTING FOR IMPROVED LIVESTOCK PRODUCTION
UNDER CLIMATIC VARIABILITY AND CHANGE IN KAJIADO, KENYA
Munyao, J. N., Kinama J.M., Kimenju J.W., Ndutu. J. M. , Mutiga, E.R. and M.W.K.
Mburu.
Department of Plant Science and Crop Protection University of Nairobi. P.O Box 29053-00625
NAIROBI
Abstract
One way of improving livestock health and productivity under the challenges of climatic
variability and change is addressed through water harvesting technologies. A study was
conducted to determine the water harvesting technologies for pasture improvement and pasture
conservation practices in Kajiado District. An evaluation of water harvesting technologies for
pasture improvement was conducted on-farm in Kajiado and on-station in the University of
Nairobi Farm at Kabete. The experiment had two fertility levels. Randomized complete block
design layout as split-split plot was adopted with cow manure (0 and 8t/ha) as the main plot,
water harvesting technology (semi-circular bands, furrows, and control) as sub-plot and grass
species (Enteropogon macrostachyus, Eragrostis superba, Cenchrus cilliaris and cowpeas
(K80)) as sub-subplots. Addition of manure resulted in a significant (P<0.05) increase in biomass
production of thet grass species together with cowpea at both sites. Total biomass produced was
higher in furrows and semicircular bands than the control. The results further indicated that E.
macrostachyus on furrows and semi circular bands produced the most biomass and had highest
ground cover, followed by C. cilliaris, while E. superba had the least at both sites. The
combination of appropriate water harvesting technologies and cow manure, which is locally
available in the cowsheds, can be adopted to improve pasture productivity in Kajiado district.
This would in turn improve the livestock productivity with the ultimate result of improved food
security and livelihoods of the pastoralists.
Key words: Cow manure, livelihoods, pasture yields, water harvesting.
aGRO 2011 Biennial Conference L1022. CONSERVATION OR DEGRADATION: APPLICATION OF REMOTE
SENSING AND GIS TO DETERMINE EFFECTS OF COMMUNITY WILDLIFE
SANCTUARIES ON LAND COVER IN PASTORAL AREAS
Muthiani, E.N 1,3, J. T Njoka1, P. I.D Kinyua1 and G.K. Gitau2
1
Nairobi. P. O. Box 29053 00625 Nairobi, Kenya
2
3
Department of Clinical Studies, University of Nairobi, Kenya. P. O. Box 29053 00625 Nairobi
Kenya Agricultural Research Institute- Kiboko Range Research Centre
Abstract
Community Wildlife Sanctuaries (CWS) has been promoted as a win-win approach for wildlife
conservation and sustainable pastoral livelihoods. Establishment of CWS in pastoral lands
involves zoning of the land into grazing and conservation areas. A study was carried out to
determine the effect CWS on land cover in pastoral group ranches in Koija, Tiemamut and
Kijabe in Laikipia North District and Girgir in Samburu East District. A combination of multitemporal Landsat (TM5 and ETM 7) and Aster satellite images for 2000, 2005, 2010 and 2011
were analysed using supervised classification. The data from images was augmented by field
observation and vegetation sampling. Seven and eight land cover types were identified in Kijabe
and Tiemamut while nine were delineated in Koija and Girgir group ranches. The land cover
types included open grass, bare ground, open herbaceous, water body, open shrub, open
woodland, closed woodland, closed shrub and riverine vegetation. The proportions of different
land cover types was significantly different (P<0.05) between the group ranches except for
closed woodland. Percent open grass cover declined at a rate of 5.92%, 2.20% and 5.18% in
Tiemamut, Kijabe and Girgir respectively but increased at a rate of 20.96%, 52.96% and 19.7%
in Tiemamut, Kijabe and Koija CWSs. Percent open herbaceous and bare ground cover
increased significantly over the ten-year period in the grazing areas while it declined in the CWS.
The deteriorating trend in some grazing areas was attributed to increased livestock grazing
intensity, climate and human utilization. Introduction of CWS seemed to contribute to
degradation in the grazing areas and an improved range condition in the CWS. The need to
implement sustainable strategies to reduce grazing pressure and rehabilitate the grazing areas is
recommended.
Key Words: Zoning, Satellite, Grazing, range condition Laikipia, Samburu
aGRO 2011 Biennial Conference L1027. SUSTAINABILITY OF DRYLAND ECOSYSTEMS AND SOCIETIES:
OPPORTUNITIES AND CHALLENGES
NJOKA J.T.
Department of Land Resource Management and Agricultural Technology, University of Nairobi.
P. O. Box 29053 00625 Nairobi, Kenya
Abstract
Dryland systems cover 41.3% of global area, support 35.5% of global population and provide
important services for both human livelihoods and global ecological sustainability. The dryland
ecosystems however are not static but respond to the global changes in climate, economic and
social political governance systems. Some of the key challenges facing sustainability of dryland
ecosystems and societies include rapid demographic changes, climate change; land degradation
through non sustainable utilization of dryland resources; loss of biodiversity; land fragmentation;
land tenure and land use changes, escalating conflicts over diminishing natural resources,
increasing vulnerability of dryland livelihoods to droughts and floods, and loss of access to
global markets. Interventions in drylands improve of our knowledge and understandingof
dryland ecosystem resilience and human adaptation strategies for coping with these changes will
contribute to sustainable management of these ecosystems. Such interventions will lead to better
decision making in promoting opportunities for sustainable land management of drylands. The
new Center for Sustainable Dryland Ecosystems and Societies at the University of Nairobi is
addressing the opportunities and challenges facing the drylands in Kenya through improved
educational curricula, generation of new knowledge through action research, outreach activities
as well as by establishing an information/knowledge exchange platform for key players in
sustainable dryland development.
Key words: Drylands, livelihoods, knowledge, management, sustainability, vulnerability.
aGRO 2011 Biennial Conference L1028. ANALYSIS OF SECONDARY LAND RIGHTS FOR ADAPTATION IN
CLIMATE DRIVEN AGROPASTORAL SYSTEMS OF SOUTH EASTERN KENYA
* Nyangito M.M., D.M. Nyariki., A. Hjort., K.O. Farah., and N.K.R. Musimba.
Department of Land Resource Management and Agricultural Technology, University of Nairobi.
P. O. Box 29053 00625 Nairobi, Kenya
*Corresponding author, e-mail: [email protected]; [email protected]
Abstract
Land fragmentation and privatization in pastoral systems in Africa has limited the application of
traditional adaptive livelihood strategies, particularly pastoral livestock mobility. This has
increased vulnerability of livestock dependent livelihoods due to climate variability and change
in the African dry lands. Reduced vulnerability to climate variability and change will depend on
enhancing adaptive strategies and mechanisms at local level. Secondary land rights have been
used to enhance mobility and flexibility in agro/pastoral systems and thus the adaptive capacity
of the systems. This study aimed at characterizing the nature and extent of use of secondary land
rights to access grazing resources and the factors affecting their application in the Kamba agropastoral system of south eastern Kenya. Direct interviews of 50 households distributed in 9
randomly selected sub-locations of Kibwezi District were conducted using questionnaires and
analyzed using econometric techniques. Seventy percent of the households used secondary rights
to secure pasture for their animals, particularly short term land leases (64%) and exchange of
bulls for ploughing (38%). Use of secondary land rights was positively and significantly
influenced by increasing livestock per adult, smallstock to cow ratio, and small farm size per
household. The amount of crop residue available and increasing grazing area per adult had a
negative effect. Secondary rights gave households flexibility in dealing with pasture shortages
during dry spells. In such agropastoral systems, grazing management strategies that are
augmented by flexible secondary land rights could be central to sustainable livestock production.
Keywords: Agropastoral systems, secondary land rights, climate adaptation
aGRO 2011 Biennial Conference L1029. IMPACTS OF CLIMATE CHANGE AND VARIABILITY ON THE LIVESTOCK
BASED LIVELIHOOD IN ENKARONI LOCATION OF KAJIADO DISTRICT
*
Okati S.J.K. , Wangia S.S.M., Mbugua P., Kimenju J.W. Mutiga E.R., Kinama J.M,
Ojoo R., Ndutu J. and Mongare P.
Faculty of Agriculture, University of Nairobi. P.O Box 29053-00625 NAIROBI
Abstract
There is need for information on the impacts of climate change and variability on the pastoral
based livelihood of Enkaroni location, Kajiado district. This study thus sought to explore the
extent to which climate change and variability is affecting the pastoral livelihood capitals. The
study analyzed climatic data collected between 1972 and 2009 visa avis the historical profile of
the community. The specific objectives of the study were to; 1) Identify the effects of seasonal
climatic variability on the livestock based livelihood assets, 2) establish impacts of climate
change and variability on physical capitals, 3) establish coping strategies being engaged by the
pastoralists. Semi structured questionnaires were administered to 178 household heads in
Enkaroni location in August 2008 and April 2009. A 4-day Participatory Rural Appraisal
involving 45 participants was also conducted and data analyzed statistically using SPSS. The
study the number of livestock owned per household declined overtime from an average of 100
heads of cattle to 4. A similar trend was also observed in terms of pasture resources like grass,
browse and water. The mean temperature had increased by about 0.4oC. As a result of increasing
water shortage more boreholes and shallow wells being drilled in the area. The main coping
strategies were charcoal burning, sand harvesting, out-migration in search of casual labour,
trading and change in dietary diversity. Climate change and variability is affecting pastoral
based livelihood in Enkaroni location negatively. Some of the coping strategies such as charcoal
burning are reducing land cover and this may aggrevate environmental degradation. Further
studies are recommended to identify sustainable climate change adaptive options for the
livelihood.
Key words: Climate change and variability, pastoral, livelihoods.
aGRO 2011 Biennial Conference L1030. ABANDONED CROPS OF NUTRITIONAL AND ECOLOGICAL
SIGNIFICANCE: A CASE STUDY OF YATTA DISTRICT, KENYA
1
Onwonga R.N, 1Kipkok B.K, 2Kyazz, F.B, 2Bareeba, F., Kabi. F., 1Wahome, R., 1Liavoga,
A.B.
1
University of Nairobi, Faculty of Agriculture, P.O. Box 29053-00625, Nairobi,
2
Makerere University, Faculty of Agriculture, P.O. Box Box 7062, Kampala, Uganda
Abstract
A case study, involving 60 representative farmers from three administrative divisions of Yatta
district, was conducted to identify abandoned crops (AC) of ecological and nutritional
significance for reintroduction. Participatory techniques were used to collect information on;
agricultural production constraints, AC of ecological and nutritional significance, reasons for
crop abandonment, pathways of nutrient losses from the farming system and locally available
resources for supporting production of AC. The constraints to crop production in the
administrative divisions were; poor soil fertility, soil erosion, unreliable rainfall, inadequate
labour and lack of farm inputs. The crops; sorghum, cassava, finger millet, sweet potatoes and
pumpkins that were popular in the 1960s and 1970s had been abandoned in favour of new crops
such as maize and horticultural crops. The key reasons for crop abandonment in the divisions
were; high input prices, a young generation disinterested in agriculture, attack by pests and
diseases, and farmers’ preference for high value crops. The principal pathways of nutrient
losses in the three divisions were; crop harvests and sales and, soil erosion. The local resources
available for supporting production of AC were manure, crop residues and compost, and trash
and stones to control soil erosion. Based on the constraints to crop production, reasons for crop
abandonment and farmers’ knowledge and resources, integrated technological packages, tailored
towards production and reintroduction of the AC crops are being tested.
Key words: Indigenous technical knowledge, participatory techniques, technological packages
aGRO 2011 Biennial Conference L1031. EFFECT OF SUPPLEMENTAL IRRIGATION ON GROWTH, YIELDS AND
WATER USE EFFICIENCY OF TOMATO (Solanum lycopersicum) AND ONION (Allium
cepa) IN KIBWEZI DISTRICT, EASTERN KENYA
Origa O. L., Gachene C.K.K., Kironchi G. and Onwong’a N. R.
Department of Land Resource Management and Agricultural Technology (LARMAT),
College of Agriculture and Veterinary Sciences (CAVS), University of Nairobi
Abstract
Field trials were conducted in Kibwezi District to examine the effect of supplemental drip
irrigation on growth, yields and water use efficiency (WUE) of tomato (Solanum lycopersicum)
and onion (Allium cepa). The specific objectives were to: (a) investigate the effect of
supplemental irrigation on growth, development and yield response of onion and tomato; (b)
determine the effect of different watering regimes on water use efficiency of onion and tomato.
Both crops were grown under three treatments- two modes of supplemental irrigation at 4-day
interval: once-a-day (T1) and twice-a-day (T2) water applications on each irrigation day, and
control (rainfed, T3). The growth parameters (plant height, numbers of leaves and branches per
plant) responded positively to the supplemental irrigation in both crops. There were significant
differences (p < 0.05) in the growth characteristics of T1 and T2 plots compared to the rainfed
ones. Supplemental irrigation also increased fruit and bulb remarkably. When compared to T3,
T1 and T2, respectively, represented a 79% and 63% increase in tomato (season 1) marketable
yields. The effect of supplemental irrigation compared to rainfed agriculture was outstanding.
The yield of onion increased by 153% and 138% in T1 and T2 plots, respectively, compared to
rainfed plots. The trial results for both crops also demonstrated that the twice-a-day supplemental
irrigation at 4-day interval (T1) was comparatively effective in enhancing yields than
supplementing at once-every-day (T2). Onion WUE increased with increasing water application,
with the results obtained in T1 and T2 being significantly higher than those of T3. In tomato,
irrigated treatments T1 and T2 had significantly lower WUE compared to T3.
Keywords: supplemental irrigation, WUE, growth parameters, yield response
aGRO 2011 Biennial Conference L1032. WATER GOVERNANCE FOR SUSTAINED ECONOMIC GROWTH AND
POVERTY ALLEVIATION: THE CASE OF AN ECONOMY SURROUNDED BY
WATER
Ramessur T. S.
University of Mauritius, Reduit, Mauritius
Abstract
Mauritius is one of the few countries in Africa where the total population has access to abundant
low priced potable water. However, with prolonged dry season caused by climate change, high
surface runoff due to the topography of the island, increased population growth/human activities,
higher water demands by industries and tourists, leakages in the water distribution network and
severe risks of water pollution arising from both industrial and non-point source pollution, it has
become crucial to address the issue of water governance. This paper aims at assessing how the
implementation of Economic Accounting for Water (EWA) contributes to water governance in
the island, through two water accounts which were compiled – water asset and physical supply
and use accounts. The study uses the indicators of the ADB, grouped under 17 headings namely:
governance at national level; policy and legislation; regulation; decentralisation; alternative
service providers; sector wide approach and PRSP; sector financial management; monitoring and
evaluation; water resources management; environmental management; transparency and
accountability; corruption; civil society participation; gender; voice and choice; rights to water
and equitable services provision. The main findings reveal that water governance has improved
in terms of many of the assessed indicators, though the link between water governance and
poverty alleviation is still blurred since this exercise just started last year and for more visible
links longer time series data will be required.
Key Words: Water Governance, Mauritius, Socio-Economic Development
aGRO 2011 Biennial Conference L1034. SYNTHESIS OF TERMITE STUDIES CONDUCTED IN THE NAKASONGOLA
ECOSYSTEM IN UGANDA
Swidiq Mugerwa12, M.M. Nyangito2 and D. Mpairwe3
1
National Livestock Resources Research Institute, P.O.Box 96, Tororo, Uganda
2
Department of LARMAT, P. O. Box 30197, University of Nairobi, Kenya
3
Makerere University, P.O.Box 7062, Kampala, Uganda
Abstract
Consumption of large quantities of grass biomass by termites is a major constraint to livestock
production in the rangelands of Nakasongola. Development of appropriate termite management
interventions in such ecosystems requires a holistic approach that considers both social and
ecological factors which influence termite damage on rangeland vegetation. We undertook a
comprehensive review and linked findings from parallel studies in the area. The review revealed
that the termite assemblages in semi-arid Nakasongola consisted of sixteen species from one
family (Termitidae), three sub-families (Macrotermitinae, Termitinae and Nasutitermitinae) and
eight genera (Macrotermes, Odontotermes, Microtermes, Pseudocanthotermes, Cubitermes,
Procubitermes, Trinervitermes and Ancistrotermes). Species from the sub-family
Macrotermitinae constituted 69% of the total number of species sampled. All the species
belonged to group I (true soil feeders) and group II (Wood, litter and grass feeders) feeding
groups. Group II species dominated the assemblages comprising of 75% of the total species.
There was a significant difference (P>0.0001) among farmers’ ranking of factors enhancing
termite damage on rangeland vegetation. Overgrazing and deforestation were ranked
significantly higher than other factors. The farmers’ perceptions were supported by results from
foraging trials that revealed that foraging intensity was highest (over 90%) and lowest (≤ 45%) in
areas with sparse and adequate basal herbaceous vegetation cover respectively. The results of the
review revealed that termite species in Nakasongola ecosystem are largely litter feeders and only
resort to grass biomass once inappropriate rangeland management techniques such overgrazing
and deforestation deprive the species of adequate litter for their nourishment.
Key words: Farmers’ knowledge, foraging intensity, assemblage, rangelands
aGRO 2011 Biennial Conference SUBTHEME 2
FOOD AND NUTRITIONAL SECURITY
aGRO 2011 Biennial Conference F2001. YIELD, SAFETY AND FUNCTIONAL PROPERTIES OF STARCH FROM
DIFFERENT KENYAN CASSAVA CULTIVARS
Aberi D.M, Lamuka P. O. and Okoth M.W.
University of Nairobi, Department of Food Science, Nutrition & Technology, P.O. Box 2905300625, Nairobi.
Abstract
Several cassava cultivars have bred for different necessary traits (disease resistant, drought
resistant and high yielding) in Kenya. However these cassava cultivars have not been assessed
for their technological usage in food systems. This study was carried out to determine if there are
any differences in yield, hydrogen cyanide content and technological or functional properties of
starch extracted from different cassava cultivars grown in Kenya. Twenty cassava cultivars were
sampled from University of Nairobi farm at Kibwezi, Kenya Agricultural Research Institute,
Kakamega and farmers in Busia County. Starch was extracted from each cultivar and dried in a
specially designed tent solar drier to final moisture of 14%. The dried starch from each cultivar
was evaluated for yield, hydrogen cyanide content and its water binding capacity, swelling
power and pasting properties. There were highly significant (P<0.01) differences in starch yield
and hydrogen cyanide content among the cultivars. Starch yield varied from 5.7% for
Mshelisheli cultivar to 29.1 % in local cultivar. The hydrogen cyanide content of starch from all
the cultivars was below the WHO recommendation of 10 mg/kg. There was highly significant
difference in water binding index among the cultivars. The water binding index varied between
0.867 for Mshelisheli cultivar to 2.420 for MH97/2270 cultivar. There was highly significant
difference in swelling power among the cultivars. The swelling power varied between 9.53 for
Migyera to 29.47 for MH95/0183. There was highly significant difference in pasting properties
among the cultivars. The peak viscosity varied between 790 for local cultivar to 882.5 for
MH97/2270 cultivar. The starch from MM97/2270 and MH95/0183 had the best combination of
functional properties, hence recommended for starch production and use in food industries.
Key words: Cassava starch, hydrogen cyanide content, functional properties.
aGRO 2011 Biennial Conference F2002. EFFECT OF PACKAGING AND STORAGE TEMPERATURE ON THE SHELF
LIFE OF CRISPS FROM FOUR KENYAN POTATO CULTIVARS
Abong’G. O1*., M.W. Okoth1., J.K. Imungi1 and J.N. Kabira2
1
Department of Food Science, Nutrition and Technology, University of Nairobi, P.O. Box 2905300625, Nairobi, Kenya.
2
National Potato Research Centre (KARI), Tigoni, P.O. Box 338, Limuru, Kenya
*
Corresponding author: [email protected] or [email protected]
Abstract
Potato crisps are known to absorb high amounts of processing oil that may undergo oxidation
and hydrolysis during storage, depending on packaging and storage temperature. These changes
may, however, have profound effects and impact negatively on product acceptability. This study
was therefore designed to determine changes in the levels of peroxides, free fatty acids and
moisture as influenced by packaging and temperature during storage of crisps processed from
four Kenyan potato cultivars. Potato tubers were processed into crisps of 1.5 mm thickness at a
frying temperature of 170oC for 3.5 min. The crisps were packaged into aluminium foil pack and
polyethylene bags commonly used by Kenyan industries and stored at 25 oC, 30oC and 35oC for a
period of 24 weeks. The results showed that aluminium foil pack was the most effective in
controlling increase in moisture content, peroxide values and free fatty acid levels. Potato
cultivar significantly (P ≤ 0.05) influenced the formation of peroxides ranging from a maximum
of 2.27 mEq kg-1 in 391691.96 to 7.44 mEq kg-1 in Tigoni. Crisps stored at 35 oC had
significantly shorter shelf life compared to those stored at 25 and 30oC. The flavor, aroma and
acceptability scores of the crisps significantly decreased and varied with cultivar and storage
temperature; scores being lower for high temperature storage. Cultivar, packaging and storage
temperature are important determinants of crisps shelf life and safety.
Key words: fat oxidation, hydrolytic alterations, peroxides, moisture buildup
aGRO 2011 Biennial Conference F2003. ENHANCING FOOD SECURITY THROUGH INCREASED POTATO
PRODUCTION IN KENYA
1*
Abong’ G. O., 2S. I. Shibairo., 3J. N.Kabira and 4J. A. Aguk.
1
Department of Food Science, Nutrition and Technology, University of Nairobi, P.O. Box 2905300625, Nairobi (Kangemi), Kenya; 2Department of Food ScienceNutrition and Technology,
University of Nairobi, P.O Box 29053-00625, Nairobi, Kenya; 3National Potato Research Centre
(KARI), Tigoni, P.O. Box 338, Limur,. Kenya; 4Department of Land Resource Management,
University of Nairobi, P.O. Box 29053-00625, Nairobi (Kangemi), Kenya
*
Corresponding author: Email: [email protected]
Abstract
Potato in Kenya is an important food and cash crop that plays a major role in food security and is
only second to maize in terms of utilization. The crop has higher yields per unit area (40 tonnes
per hectare) than most of the major food crops including maize and beans. Potato production has
been increasing due to economic decline of competing cash crops such as maize, coffee and
pyrethrum, and increasing demand from consumers and processors. Approximately 500,000
Kenyan smallholder potato farmers produce about 1 million tonnes from 100,000 ha of cultivated
land area. The potato in Kenya, just like the other roots and tubers in the Sub-Saharan Africa
(SSA) is a major source of sustenance. It accounts for more than 20 % of calories consumed
world over. Its production and processing ensures employment to thousands of Kenyans. Besides
general home use, potato chips (French fries), crisps and frozen fries, whose demand has rapidly
increased due to rapid growth of fast food restaurants and snack bars in the urban areas, are
among many products processed from potatoes. Due to erratic rainfall patterns experienced in
Kenya, production of maize as a staple crop has been unstable. Recent years have seen a
decrease in maize and other cereals production. Unlike the maize crop that takes at least 5
months to mature, potatoes have short growth cycle maturing at an average period of 3 months
and can be easily integrated into existing farming systems. Potatoes can therefore be successfully
grown during the short rain periods which have become common in Kenya. This paper looks at
potatoes as a possible food security crop in the face of a changing Kenyan weather pattern.
Key words: potato, staple, calories, food security
aGRO 2011 Biennial Conference C2008. DEVELOPING DROUGHT TOLERANT MAIZE GENOTYPES IN KENYA:
SELECTION FOR ANTHESIS TO SILKING INTERVAL
Cheserek J., E.C.K. Ngugi and Chemining’wa G.N.
Dept of Plant Science and Crop Protection, Faculty of Agriculture, University of Nairobi, PO
BOX 30197, Nairobi, Kenya
Abstract
Drought is one of the major abiotic stresses that causes yield loss in the tropical environments
and selection for drought tolerance will improve crop yields. Flowering in maize has been
identified as a crucial trait in breeding for drought tolerance. Delay in silking leads to a long
anthesis to silking interval (ASI) and therefore poor kernel set. A study was conducted in
2008/2009 at Kiboko and Kabete field station and the objectives were: (i) to evaluate parental
lines under managed stress environment and (ii) to select genotypes from segregating
populations using earliness and anthesis silking interval as the key secondary trait. Two open
pollinated varieties and an inbred line were crossed to four CIMMYT lines to generate F1 and F2
generations. Combined analysis of variance was done for the secondary traits including anthesis
to silking interval . There was significant difference among the open pollinated varieties
(OPV’s), and inbred lines, in all the secondary traits except for the ears per plant. The average
grain yield of the inbred lines and of OPV’s was 1.7 t/ha. The correlation between ASI to; kernel
weight was, (r=0.763, P≤ 0.01) days to anthesis (r= -914, P≤ 0.01), days to silking (r= -0.811, P≤
0.05) and leaf senescence (r=0.864, P≤ 0.01). ASI had low heritability because the genotypes in
which it was measured were well watered. Short ASI and earliness were used in selecting the F2
population for evaluation in the next generation. It was possible to combine both earliness and
short ASI which are controlled by different gene systems into the same genotype. This study
recommends that the F2 genotypes selected for short ASI and early-maturity be evaluated further
in the F3 generations under both well-watered and water-stress multi-locational trials.
Key Words: Anthesis to silking interval, drought tolerance, heritability.
aGRO 2011 Biennial Conference F2009. SUSCEPTIBILITY OF LOCALLY GROWN MAIZE VARIETIES TO MAIZE
WEEVIL (Sitophilus zeamais Motsch)
Tom F. K., F. M. Olubayo, J. W. Muthomi and G. N. Chemining’wa
Department of Plant Science and Crop Protection, Faculty of Agriculture, University of Nairobi,
P.O Box 29053-00625, NAIROBI
Corresponding author:
Abstract
Storage insect pests of maize cause weight and quality loss. Although insecticides and fumigants
are available, use of resistant varieties is preferred due to low cost, have no adverse effect on
environment and leave no toxic residues on food products. The objective of this study was to
evaluate locally grown maize varieties for susceptibility to maize weevil (Sitophilus zeamais
Motsch). Sixteen varieties were screened in the laboratory and field over two growing seasons.
Grain samples from field experiments were incubated for two months and insect pests that
emerged counted and identified to species level. Insect-free and undamaged samples of each
variety were infested with unsexed four-week old weevils and incubated for three months and the
percentage grain damage, seed weight loss and number of F1 progeny determined. Varieties DK
8031 and H513 had significantly high (P≤0.05) infestation of up to 32 insects per 100 grams
while Katumani had no insect infestation. Inbred line CKPH080020 had significantly low index
of susceptibility, longer median development time, and number of F1 progeny. It was observed
that an increase in the F1 progeny resulted in increased seed damage and seed weight loss. The
study showed that there exists resistance among the maize varieties tested. The resistance in
some of the varieties tested could be useful in improving local popular maize varieties through
breeding. The resistant varieties identified could be further evaluated for possible promotion to
farmers in insect damage prone areas.
Key words: Resistance, Sitophilus zeamais, varieties, resistance, Zea mays.
aGRO 2011 Biennial Conference C2109. EFFECT OF PREHARVEST AGRO-ECOLOGICAL CONDITIONS ON THE
POSTHARVEST QUALITY AND SHELF LIFE OF MANGO FRUITS, Mangifera Indica
L CULTIVAR TOMMY ATKINS
Githiga Ruth1, Ambuko, J1, Hutchinson M. J1 and Owino W.O2
1
Department of Plant Science and Crop Protection, University of Nairobi
Department of Food Science and Postharvest Technology, Jomo Kenyatta University of
Agriculture and Technology
2
Abstract
Preharvest production factors including agro-ecological conditions and cultural practices have
been reported to affect the fruit quality potential at harvest and postharvest characteristics. This
study was conducted to compare the quality and postharvest shelf life of mango fruits produced
under two contrasting agro-ecological conditions (high potential versus low potential) found in
two districts (Embu and Yatta respectively) of Eastern Province of Kenya. The two locations
differ in rainfall amounts and distribution, temperature and soil conditions. Fruits produced in the
two locations were harvested at three stages of maturity; stage 1 (150days after bloom), stage 2
(165 days after bloom) and tree ripe stage (180 days after bloom). Fruits harvested at stage 1 and
2 were stored at ambient room conditions and three fruits sampled every two days for evaluation
of physiological and physicochemical parameters associated with ripening and fruit quality. The
parameters evaluated include ethylene evolution, respiration, changes in peel/flesh firmness and
color, cumulative weight loss, changes in 0brix, soluble sugars, ascorbic acid, ß – carotene and
mineral nutrients. A hedonic scale was used to evaluate the sensory properties of the tree ripened
fruits from the two locations by an untrained taste panelists Significant (P<0.05) treatment
effects were observed between fruits harvested from the two agro-ecological zones. Fruits from
the lower potential (drier) Yatta district had higher flesh firmness, levels of 0brix, soluble sugars,
ß – carotene and ascorbic acid levels compared to fruits from the higher potential district
(Embu). The Yatta fruits also had better sensory properties as evinced by higher scores on
hedonic scale. Fruits from Embu deteriorated faster during storage as evidenced by an earlier
respiratory climacteric and higher respiration rates and cumulative weight loss and lower flesh
firmness throughout storage. These results confirm that preharvest production conditions
significantly affect fruit quality and the postharvest behavior and should be considered in
processing and postharvest handling of fruits.
Key words: Mango, Fruits, preharvest, postharvest, quality, ripening
aGRO 2011 Biennial Conference C2011. EFFECT OF FARMYARD MANURE AND CAN ON YIELD AND QUALITY OF
Amaranthus lividus IN LUGARI DISTRICT, IN KENYA.
1
Hutchinson M.J and 2Nipher Olubayo
1
University of Nairobi, Department of Plant Science and Crop Protection; P.O. BOX 2905300625, Kangemi, Nairobi
2
Kenya Plant Health Inspectorate Service; P.O. Box 49592-00100 Nairobi.
Abstract
The main objective of the study was to evaluate the effect of Farm Yard Manure (FYM) and
calcium ammonium nitrate (C.A.N) on vegetative growth, leaf yield, vitamins A and C as well as
nitrates (anti-nutrients) content of vegetable amaranth in Lugari District. The effect of traditional
method of cooking on the levels of these micronutrients and anti-nutrients was also evaluated.
The incorporation of different concentrations of both FYM (10-20 tons/ha) and C.A.N (100-400
kg/ha) significantly improved the vegetative aspects and yield of the plant, during the rainy and
dry seasons. The FYM and CAN, however, reduced β-carotene (vitamin A pre-cursor) content of
the vegetable amaranth, with slightly higher accumulation during the rainy season than during
the dry season. Application of different concentrations of FYM and CAN fertilizer as well as the
plant age showed no clear trend on the vitamin C content in both seasons. However, there was a
greater accumulation of nitrates, especially with age of the plants when FYM and CAN was
applied. Cooking during both seasons reduced the beta-carotene, vitamin C and nitrates by up to
30%, 70%, and more than 50%, respectively. In summary, addition of FYM and CAN
significantly increased the yield and quality of vegetable amaranth, but also increased the nitrate
anti-nutrients while cooking significantly decreased the said attributes.
Key Words: African leafy vegetables, Amaranthus lividus, Farm Yard Manure, Inorganic
fertilizers, nutritional security, vitamins
aGRO 2011 Biennial Conference C2120. SPATIAL AND TEMPORAL FLUCTUATION OF MALIARPHA SEPARATELLA
RAGONOT, LEPIDOPTERA: PYRALIDAE AT MWEA IRRIGATION SCHEME.
Kega, V.M. , 1 J.H.Nderitu2., F.M Olubayo1 and M. Kasina 3
1
Department of Plant Science and Crop Protection, College of Agriculture and Veterinary
Services, University of Nairobi, P.O Box 29053- 00800 Nairobi
2
Mount Kenya University, P.O Box, 342-01000, Thika
3
Kenya Agricultural Research Institute- P.O. Box 58711-00200 Nairobi
Abstract
The African white rice stem borer (Maliarpha separatella Ragonot) is a major constraint to rice
production in Kenya, particularly to the aromatic Basmati variety which is highly susceptible to
the pest. To understand and develop appropriate management packages, the African white rice
stem borer population dynamics were studied at Mwea irrigation scheme in Central Kenya,
where most of the rice in Kenya is grown. This was done for two consecutive years in both the
wet and dry periods. Sampling was done fortnightly in farmer fields located in different parts of
the scheme and outside the scheme. The farms sampled represented various water provision
schedules (Intermittent wetting and drying, rain fed, flood irrigated, sporadic irrigation), five
planting time regimes (on season, double cropping, off season, ratoon, late planting, fallow), and
three management styles (controlled by National Irrigation Board (N.I.B), Not controlled by
N.I.B and, outgrowers). During each sampling, one metre square quadrant was used randomly
and pest counted on all the plants within the quadrant. Dead tillers and panicles with white heads
were also counted. The number of tunneled tillers at harvest was used to represent M. separatella
densities. Results show that the number of M.separatella varied significantly (p<0.05) in the
scheme. Highest numbers of tunneled tillers were in Non N.I.B controlled fields with sporadic
irrigation (8.52) and the lowest in the N.I.B controlled flood irrigated (1.43) and this was
significant (p<0.05). Pest densities were also high in off season planted rice (9.24) and lowest on
ratoon crop (1.62) p<0.05. From the above results it is recommended that off season planting of
rice be discouraged and that efforts be made to ensure that farmers synchronize planting dates
and other cultural practices for the crop, within the scheme and in rice farms outside the scheme.
Key words: Population dynamics, Maliarpha separatella, Mwea irrigation scheme
aGRO 2011 Biennial Conference C2016. TAPPING THE UNDERUTILIZED POTENTIAL OF SEEDLING SUPPLY
SYSTEMS FOR IMPROVING MANGO PRODUCTIVITY
Kehlenbeck K. 1*, E. Rohde1, Njuguna J.K.2, Omari F.2, Finyange, P., Wasilwa L.2,
Jamnadass R.1
1
World Agroforestry Centre ICRAF, Tree Genetic Resources and Domestication, Nairobi, Kenya
2
Kenyan Agricultural Research Institute KARI, Dept. Horticulture, Nairobi, Kenya
*
Abstract (C2016)
Mango (Mangifera indica L.) is one of the high potential fruits in Kenya, suitable for different
agro-ecological zones (AEZ). Mango cultivation contributes to food/nutrition security and
income generation. Its potential has not been fully tapped due to several constraints along the
value chain. Challenges start with the input supply, particularly poor access of farmers to quality
planting material. Nursery operators and farmers lack information about available mango
varieties and their suitability for certain AEZs. The study’s objective was to document mango
varieties at selected motherblocks and nurseries at five stations of the Kenya Agricultural
Research Institute (KARI) and six prison farms in Central, Eastern and Coast Provinces.
Varieties in the motherblocks were recorded and trees counted. Nursery operators were
interviewed about varieties and sale of seedlings. A total of 57 mango varieties were found,
ranging from 10 to 36 varieties per motherblock. However, 23 of the 57 varieties were found at
just one single location. In the nurseries, a total of 16 out of the available 57 mango varieties
were found, ranging from 4 to 11. Just five varieties were produced in high quantities (Apple,
Kent, Ngowe, Tommy Atkins and Van Dyke). Thus, most of the available genetic resources are
not utilized. The 41 neglected varieties may offer desired characteristics such as pest/disease
tolerance or early/late yielding, but their potential has yet to be evaluated. Livelihoods of farmers
in remote areas with a high potential for mango cultivation could be enhanced by facilitating
their access to improved planting material of suitable varieties.
Keywords: intra-specific diversity, mango variety, motherblock, nursery, value chain
aGRO 2011 Biennial Conference C2017. GENETIC DIVERGENCE IN Jatropha curcas, A BIOFUEL FEEDSTOCK IN
KENYA.
*1Ngugi E.C.K., Nabiswa A.1 and Kithinji J.2
1
Department of Plant Science and Crop Protection, University of Nairobi. P.O. Box 29053,
Nairobi, Kenya.
2
Department of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi, Kenya.
* Corresponding authors. E-mail: [email protected] and [email protected]
Abstract
The objectives of this research were to estimate the genetic divergence among genotypes of
Jatropha curcas L based on phenotypic traits; to determine the relative importance of the
distinguishing traits of genotypes and indicate potential parents to establish an improvement
program for early maturity and high yielding cultivars. Forty nine genotypes of Jatropha curcas
collected from different regions of Kenya and around the world were studied for the following
traits. Plant height, girth diameter, number of branches, leaf type, days to flowering (50%), and
female: male flower ratio, number of fruits per plant and yield (kg), seed weight (100), seed
moisture and oil content. For analysis of genetic divergence Mahalanobis' D2 statistics, canonical
variables and Tocher cluster method were used. The genotypes were grouped into four clusters.
Cluster III, IV, I and II comprised 20, 14, 9 and 6 genotypes, respectively. The analysis further
indicated that the genotypes of common geographical origin or same location were grouped into
different clusters, suggesting a lack of relationship between genetic and geographical diversity.
The highest inter-cluster distance was observed between II and IV followed by I and III which
may serve as potential parents for new gene combination. It has been shown that plant height,
leaf type, branching and flowering contributed most to the genetic divergence among the
genotypes.
Key words: Jatropha Curcas, Genetic divergence, Mahalanobis’ D2 statistics.
aGRO 2011 Biennial Conference C2018. GENOTYPE-ENVIRONMENT INTERACTIONS OF Jatropha curcas GROWTH
AND YIELD COMPONENTS
*Ngugi E.C.K. and Nabiswa Alex
Department of Plant Science and Crop Protection, University of Nairobi. P.O. Box 29053,
Nairobi, Kenya.
*Corresponding author: [email protected]
Abstract
Seeds harvested from Jatropha curcas L can be used as raw material for biodiesel and bioenergy.
The potential to spur rural economy and create a state of self sustainability is immense.
Successful commercial cultivation is dependent on use of best yielding and stable genotypes
which are identified by growing different accessions in different environments. However
research on the stability of genotypes currently grown in Kenya is scarce. The objective of this
study was to evaluate the effects of genotype-environment interaction and determine stable
genotype that can be recommended to farmers and used in a breeding program. Using Eberhart
and Russsell method, stability analysis was conducted on plant height, girth diameter , number of
branches, days to flowering , female: male flower ratio , number of fruits, seed weight (100) ,
seed moisture and oil content of forty nine accessions from two trials in different environments
(Kibwezi and Thika ).Time by location and location variability were the sources of interactions.
Stability analysis showed that KJ2, KJ4,KJ6,KJ7,KJ12,KJ26,KJ27,KJ37,KJ39,KJ42 and KJ 44
were location specific while KJ3 ,KJ8,KJ19, KJ24 , KJ35,KJ45 and KJ46 showed less variation
at the two sites. The rest of the 31 genotypes showed fluctuation between and within the two
environments. The stability parameters that were indicative for adaptation were height,
branching, days to flowering and number of fruits per plant for the first group while plant height
and branching were evident for the second group respectively. Girth diameter, seed moisture and
oil content varied in all genotypes across the environments.
Keywords: Jatropha curcas L, biodiesel, stability parameters, accessions
aGRO 2011 Biennial Conference C2023. THE EFFECT OF GRAIN MOISTURE CONTENT ON THE EFFICACY AND
PERSISTENCE OF LOCAL INNERT DUSTS AGAINST SITOPHILUS ZEAMAIS IN
STORED MAIZE
1*
Khakame S.K.., P. Likhayo2 ., F. M. Olubayo1and J. H. Nderitu1
1
Department of plant science and crop protection, Faculty of Agriculture, University of Nairobi,
P.O. Box 29053 - 00625, Nairobi, Kenya.
2
Kenya Agricultural Research Institute, P. O. Box 14733 – 00800, Nairobi, Kenya.
*
Abstract
While inert dusts are known to control insect pests, the efficacy of locally mined inert and
botanical dusts is scantly documented. The effectiveness of Kensil superfine®, ash and neem
seed cake dusts was evaluated in the laboratory to determine the effect of grain moisture content
and length of storage on their efficacy. Maize grain at 10, 12, 14 and 16% moisture content were
admixed with maize cob ash, bean trash ash, neem seed cake powder and Kensil superfine®
dusts at a dose rate of 0.9% w/w. Actellic super® and Spintor® applied at the rate of 50g/90 kg
grain and Dryacide® at 0.8% w/w were included as positive controls. Untreated maize grain
served as the negative control. Thirty (30) unsexed two –week-old Sitophilus zeamais adults
were introduced in the treated maize. The treatments were replicated four times and held
undisturbed for 14 days at ambient conditions (27oC and 67% r.h.), after which mortality was
assessed. To determine persistence of the dusts, 4kg maize grain was admixed with each
treatment as described above and put into the 5kg capacity hessian baglets, replicated four times.
Untreated grain acted as control. Adult S. zeamais (population of 1500) were put in the plastic
Petri dish and left to infest the baglets naturally. The results showed that moisture content at
which effective control of Sitophilus zeamais was achieved for both inert and conventional
insecticide dusts was 12 – 13%. The dusts would be useful in crop protection application as they
perform well within the maximum limit of grain moisture content for safe storage of
commodities. Neem seed cake powder recorded greater grain weight loss (>13%) than the rest
of the treatments (<7%). Dryacide® performance (2% weight loss) was superior to all the dusts
after 9 months storage period. Further studies are required to determine the potential usefulness
of Kensil superfine® dusts in the management of storage insect pests complex.
Key words: Inert dust, botanical dust, diatomaceous earth, Sitophilus zeamais, weight loss,
stored maize
aGRO 2011 Biennial Conference C2024. UTILIZATION OF CULTURAL METHODS FOR CONTROLLING APHID
VECTORS OF PASSIONFRUIT VIRUSES
Kilalo D.C1, Olubayo, F.M1, Ateka, E.M2, Hutchinson, M.J1 and Kimenju, J.W1
1
Department of Plant Science, University of Nairobi, P. O. Box 29053 00625 Nairobi
2
Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology,
P. O. Box 62000, 00200 Nairobi
Abstract
Passionfruit (Passiflora edulis Sims) is an important fruit crop that is grown mainly by small
scale farmers for nutrition, employment creation and income generation. Insect pests and
diseases, high establishment costs, inadequate clean planting materials, drought and declining
soil fertility are the constraints to improvement of passionfruit production in Kenya. Passionfruit
growth is severely limited by viruses which are transmitted by aphids in a non-persistent manner.
The study was conducted in 2008 and 2009 to investigate the effect of cultural methods on
population densities of the aphid vectors. Field experiments were established in a randomized
complete block design with four replicates in Kabete field station and Embu (four farmers’
fields). The treatments were white plastic reflective mulch, treated yellow material trap, mineral
oil and unmulched/untreated control where aphids were monitored weekly using yellow water
pan traps in the wet and dry seasons. Reflective mulch had significant effect (p<0.05). on aphid
population density over control, yellow material trap and mineral oil at both sites. Mulch had a
significant effect in reducing Aphis gosypii, Ropalosiphum maidis, Acyrthosiphon pisum and
Macrosiphum euphorbiae which are also reported vectors of CMV and CABMV. Aphid
populations peaked only once in June coinciding with the major season for growing food crops.
All the treatments achieved better effect when population densities were higher (long rain
season) than when they were low (in dry season). Reflective mulch can decrease aphid
population density in passion fruit orchards and can be used as an alternative cultural control to
reduce vector activity and spread of woodiness disease.
Key words: Passifloraceae, cultural control, CABMV, CMV, woodiness disease
aGRO 2011 Biennial Conference C2025. BREEDING DROUGHT TOLERANT BEAN VARIETIES IN EASTERN
AFRICA
1*
Kimani P.M. and S. Beebe2
1
Department of Plant Science and Crop Protection, University of Nairobi, P.0. Box 29053
Nairobi, Kenya
2
CIAT, A.A. 6713, Cali, Colombia.
*Corresponding author: [email protected],[email protected]
ABSTRACT
Development of drought resistant varieties is one of the most important strategies for coping with
frequent droughts in bean production areas in eastern Africa. Drought resistant bean varieties are
particularly important for small holder farmers who have few other alternative and practical
options of reducing adverse impacts of drought stress. The objective of this study was to evaluate
bean germplasm for tolerance under moderate to severe drought stress field conditions. Thirtysix small seeded advanced bean lines were evaluated in a 6 x 6 lattice design in drought stressed
and non-stressed treatments at Thika for three years. Grain yield was used as the primary
selection criterion. Significant (P>0.05) environment x stress levels, genotype x stress level,
genotype x environment interactions were detected. Drought intensity (DII) was highest during
the short rain season (DII = 0.5810) and lowest during the long rain season (DII= 0.3918). Yield
reduction due to drought was highest during the first short rain season (58%) but remained at
40% during subsequent long and short rainy seasons. SEA 23, RAB 608, SEA 16 and RAB 618
were the best yielding lines under stress and non-stress environments. These four lines
consistently out yielded all the checks. Yield advantage of the best nine lines varied from 18 to
66.7% under drought stress conditions compared to the drought susceptible and tolerant checks.
SEA 16 showed the lowest drought susceptibility index (DSI). Results of this study indicate
new possibilities of stabilizing bean yields in drought prone environments. Selected lines can be
utilized in breeding drought tolerant bean cultivars.
Key words: common bean, drought susceptibility index, drought intensity index
aGRO 2011 Biennial Conference C2026. MARKER ASSISTED GAMETE SELECTION FOR MULTIPLE DISEASE
RESISTANCE OF COMMON BEAN (Phaseolus vulgaris L) IN KENYA
Kimani1 P.M., M. K. Bogori1, J. Orende1, R. D. Narla1, S. Njuguna1, S. Musyimi1, E. C.
Ngugi1 and P. Gepts2
1
Dept of Plant Science and Crop Protection, University of Nairobi, Nairobi, Kenya
2
Dept of Plant Science and Range Sciences, University of California, Davis, USA
*Corresponding author: [email protected],[email protected]
Abstract
Breeding beans for multiple constraint resistance in eastern Africa has traditionally relied on
classical approaches which have resulted in slow progress towards the release of new varieties.
Moreover, breeding programs have been dependent on erratic and unevenly distributed disease
epiphytotics to identify genotypes with multiple resistance. It has been suggested that use of
markers linked to resistance genes can improve precision, shorten duration of development of
new varieties and improve efficiency of breeding programs. The objective of this study was
validate the resistance of angular leaf spot, anthracnose, bean common mosaic virus, bacterial
common blight and root rotsin locally popular bean varieties. Another objective was to develop
breeding populations with multiple disease resistance genes and assess the potential of
polymorphic markers in selection of multiple resistance genes. Thirty-one bean varieties and
advanced lines were inoculated with isolates/strains of the five diseases in the greenhouse and
screened for polymorphism with 18 SSR and SCAR markers at Kabete. Field Station of the
University of Nairobi, Kenya. The results showed that none of the commercial cultivars was
resistant to all five diseases. Resistance to angular leaf spot in Mex 54 and G10909, anthracnose
in G2333, bean common mosaic virus in BRB 191, common bacterial blight in VAX 6, and root
rots in RWR719 and in AND 1062 were validated. Commercial varieties were polymorphic for
markers linked to at least two diseases. Twelve new male gametes with combinations of
resistance genes were developed. These results indicate that development of new bean varieties
with multiple disease resistance using markers is feasible. Polymorphic markers can be used to
identify male gametes with specific resistance genes for introgression to susceptible varieties and
in identification of desirable recombinants during the early generation.
Key words: Multiple resistance, gamete selection, marker assisted breeding, common bean
C2027. BREEDING MICRONUTRIENT DENSE BEAN VARIETIES IN EASTERN
AFRICA
aGRO 2011 Biennial Conference 1
Kimani P.M., S. Beebe2 and M. Blair2
1
Department of Plant Science and Crop Protection, University of Nairobi, P.0 Box 29053-00625
Nairobi, Kenya
2
CIAT, A.A. 6713, Cali, Colombia
Corresponding author: [email protected] : [email protected]
Abstract
Micronutrient malnutrition is one of the most serious health challenges facing vast sectors of
Africa’s population and other regions. Dietary improvement through bio-fortified food crops is
probably the most effective and sustainable strategy for reducing micronutrient deficiencies. A
regional breeding program was initiated in 2003 to develop and disseminate micronutrient dense
bean varieties in ten countries in eastern Africa. The specific objectives were: (i) to characterize
the variation of grain iron (Fe) and zinc (Zn) concentration, and (ii) identify lines which could be
fast-tracked as mineral dense lines for cultivation by farmers in regions with severe Fe and Zn
malnutrition. More than 2849 accessions were collected from East and Central Africa and 1,412
accessions were screened for Fe and Zn concentration. Results showed that considerable genetic
variation exists to facilitate improvement of iron by more than 80%, and zinc by more than 50%.
Grain iron concentration varied from 40 to over 100 ppm. Zinc concentration varied from 18 to
over 50 ppm. Genotypes with high levels of iron included Maharagi Soja, Gofta, AND 620,
MLB 49 89A, HRS 545, Nakaja, VCB 87013, Nain de Kyondo, TY 3396-13, PVA 8, Nguaku
Nguaku, Urugezi, Lib 1, Roba-1 and Mwamafutala. Results showed that bean leaves have ten
times more iron than grain. These results demonstrate that enhanced utilization of mineral dense
beans can significantly contribute to alleviation of micronutrient deficiencies and promote better
human health and productivity. Key words: common bean, bio-fortification, germplasm, micronutrients
C2028. MARKER-ASSISTED INTROGRESSION OF STAY-GREEN TRAIT IN A
KENYAN SORGHUM VARIETY
1
1
Kimani W. , K. Ngugi, 1 D. Kiambi, 2 E.W. Mutitu, 1 S. De Villiers 2
aGRO 2011 Biennial Conference University of Nairobi, Faculty of Agriculture, Department of Plant Science and Crop Protection,
P.O. Box 29053-00625, Nairobi Kenya.
2
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 3070900100, Nairobi Kenya.
Abstract
This study was aiming to improve food security in Kenya through the development of a drought
tolerant sorghum variety by the introgression of stay green QTLs. Marker-assisted backcross
breeding was utilized to transfer stay-green QTLs from the Ethiopian donor parental line E36-1
into a Kenyan farmer-preferred variety, Ochuti as the recurrent parental line. E36-1 has 3 stay
green QTLs located at three linkage groups of sorghum genome (SBI-01, SBI-07 and SBI-10).
Five foreground markers flanking stay green QTLs at linkage groups SBI-07 and SBI-10 that
were polymorphic between the two parental genotypes were used to identify true F1 individuals.
Only two of the possible three QTLs namely, SBI-07 and SBI-10 were identified as having been
transferred into three individual genotypes. This is because no polymorphic markers flanking
stay-green QTL at linkage group SBI-01was available for this particular study. The identified F1
genotypes were used as the female parents in the generation of 128 BC1F1 individuals. About
25% of the BC1F1 progenies that were genotyped had at least one QTL introgressed. Thirty
polymorphic SSR markers were used to select 20 BC1F1individuals that had a higher proportion
of recurrent parent genome. These were backcrossed to recurrent parent to generate 157 BC2F1
family lines. These were screened with the five foreground SSR markers where 45 individuals
were confirmed to be having among them single and double introgressions of stay-green QTL(s).
This study shows that, marker-assisted backcrossing can successfully and accurately transfer
genomic regions contributing to the stay green trait into Kenyan sorghum prone to drought. This
was possible with the availability of polymorphic co-dominant markers like SSRs.
Key words: marker-assisted backcross breeding, stay green.
C2032. PERFORMANCE OF FARMER-PREFERRED MAIZE VARIETIES
INTERCROPPED WITH BEANS IN SEMI-ARID KENYA
Kitonyo, O.M1, G.N. Chemining’wa2 and J.W. Muthomi2
International Maize and Wheat Improvement Center (CIMMYT) – Nairobi, P.O. Box 2041 –
00621, Nairobi.
2
Department of Plant Science and Crop Protection, University of Nairobi, P.O Box 29053 –
00625, Kangemi, Nairobi.
Corresponding author’s: [email protected]
Abstract
Recurrent droughts have resulted to increased maize crop failures and food insecurity especially
in semi-arid regions of Kenya. To cope, farmers are advised to adopt drought tolerant maize
varieties and maize-legume intercropping as a diversification strategy. As such, a study was
conducted in Machakos, Mwea and Waruhiu to determine the performance of maize varieties
currently grown in the semi-arid regions and their compatibility with a commonly grown bean
variety, KB 1. Sixteen maize varieties were grown either as sole crops or intercropped with KB
1. The experiments were laid out in a RCBD with split plot arrangement and replicated thrice.
Maize variety and intercrop system were assigned to the main and sub-plots, respectively. Data
collected included plant height, nodulation, shoot biomass, stand count, lodging, days to 50%
flowering and maturity, yield and yield components. Land equivalent ratio (LER) and monetary
advantage (MA) indices were calculated to evaluate productivity of intercropping. Results
indicated that varieties KCB, Katumani, DHO 1, DHO 2, DK 8031and Duma 43 are suitable for
these regions. Except DK 8031 and Duma 43 which seemed to tolerate drought, the other
varieties escaped drought by maturing early. Further, these varieties were found to be compatible
with beans in an intercrop system. However, beans yield was significantly affected by the maize
component in the intercrop system and declines of 52% to 59% were observed. According to
LER and MA indices, intercropping was superior to sole cropping. To increase food production,
these drought escaping and tolerant varieties and maize-bean intercropping should be considered.
Key words: Maize, beans, intercropping, drought tolerance, semi-arid, Kenya
C2034. THE IMPACT OF PLANTING DENSITY AND WEEDING REGIMES ON
MAIZE AS A FOOD AND FODDER CROP
*Kivuva, B.M., 2M.W. K Mburu., 3J. M. Maina., and 4A. J .Murdoch
1
Kenya Agricultural Research Institute, National Agricultural Research Centre, Muguga, P O
Box 30148, 00100, Nairobi, Kenya.
2
Department of Crop Science, University of Nairobi, P O Box 30197, Nairobi
3
Kenya Agricultural Research Institute, National Agricultural Research Laboratories, P.O Box
14733, Nairobi Kenya
4
School of Agriculture, Policy and Development, The University of Reading, P O Box 237,
Earley Gate, Reading RG6 6AR, UK.
*correspondending author Email: [email protected]
Abstract
Dairy farmers in Kenya grow maize for forage and food. They use maize planting density,
weeding regimes and thinning to regulate the quantity of forage from both maize and weeds. The
objective of this work was to evaluate the effects of weeding and planting density on maize
forage and grain yield and quality of forage. Field experiments were conducted at the Kenya
Agricultural Research Institute, Muguga for two seasons (October 2001 to August 2002).
Weeding regimes included: maintaining the plots weed free by hand weeding throughout the
growth period (W1), not weeded (W2), herbicide (W3) and hand weeding twice (W4). The
maize planting densities were 9 plants m-2 (D1) and 18 plants m-2 (D2). The experimental design
was randomized complete block design replicated four times. Maize in both D1 and D2 was
thinned to 4 plants m-2 at tasseling stage and the thinnings were assessed as forage. Stover and
weeds with forage value and maize yield were assessed at harvest. Thinnings biomass was higher
where weeds were controlled (W1, W3, W4) and D2 than D1. Maize grain yield was higher in
D1 than D2. Maize thinnings had higher digestibility and crude protein than stover. Herbicide
was more effective in controlling weeds than hand weeding twice. Although not weeding
reduced forage and grain yield, at least 55 % of the weeds were edible and of high quality and
could be used as forage and vegetable, but the weed biomass was much lower than of maize. In
conclusion, dairy farmers could practice plant maize at 18 plants m-2 and hand weed twice to
increase forage quantity and quality while ensuring moderate maize grain production.
Keywords: Dry m a t t e r c o n t e n t , c r u d e p r o t e i n , d i g e s t i b i l i t y
aGRO 2011 Biennial Conference C2037. INFLUENCE OF FERTILIZERS ON STRIGA ASIATICA REPRODUCTION
AND SORGHUM GRAIN YIELD IN DODOMA, TANZANIA
Kudra, A1. Chemining’wa G. N. 2 Sibuga K. P., 3R. N. Onwong,a1
1
Department of Land Resource Management and Agricultural Technology, University of Nairobi
3
Department of Crop Science and Production, Sokoine University of Agriculture
2
Abstract
The measures for Striga management are hindered by unique survival strategy of the weed,
whereby it produces large amount of seeds. Therefore, prevention of build up of the Striga seed
bank through cultural practices remains an essential component in Striga control. The influence
of organic and inorganic fertilizer on Striga reproduction and sorghum grain yield was studied
for two consecutive years (2009/2010 and 2010/2011) at Hombolo Research Station-Dodoma,
Tanzania. Four fertilizer types: farmyard manure (5.9 tons/ha), chicken manure (2.5 tons/ha),
urea (50 kg N/ha) and triple superphosphate (TSP) (40 kg P/ha) were used. The experimental
design was randomized complete block design replicated four times. Striga plants supplied with
chicken manure, urea and TSP had significantly fewer capsules per plant than farmyard manure
treated and control (without fertilizer application) plants. Where TSP fertilizer was applied there
was high Striga plant density, increased intra-specific competition and consequently reduced
Striga biomass and capsules number per plant. In plots where chicken manure was applied
sorghum plant height, above-ground biomass, mean panicle length and grain yield relative were
higher compared to all other treatments. Urea, TSP, and farmyard manure did not significantly
affect sorghum growth and yield parameters. Striga biomass and numbers were negatively
correlated with sorghum grain yield. Based on this study, urea and chicken manure have the
potential to reduce Striga reproduction. Even though a fertilizer plays a significant role in Striga
reproduction, the use of fertilizer alone is not enough to reduce the Striga seed inputs and longterm effect on seed bank. Chicken manure can be used to improve sorghum production.
Key words: Striga asiatica, reproduction, fertilizers, Sorghum, intra-specific competition
aGRO 2011 Biennial Conference A2039. MINERAL STATUS OF SHEEP AND GOATS GRAZING IN THE
RANGELANDS OF NORTHERN KENYA
Lengarite M.I. a ., P.N. Mbuguab., C.K. Gachuirib., and L.W.Kabuageb
a
Kenya Agricultural Research institute, KARI-Marsabit, P.O Box 147, Marsabit, Kenya
b
Department of Animal production, Faculty of veterinary medicine, University of Nairobi, Kenya
Abstract
A study was conducted in dry and wet seasons to determine macro and micro mineral status of
growing sheep and goats in arid rangelands of northern Kenya. Forty four healthy sheep and
goats (1-2 year old), randomly purchased from flocks/herds in Merille location, Marsabit South
District were sacrificed to obtain whole liver and 12th carcass ribs. Homogenized liver samples
pooled from all lobes and defatted bone ash (DFBA) from whole left and right 12th ribs were
used for Ca, P, Mg, Cu, Fe, Zn and Mn analysis. Liver analysis, showed that in sheep, with the
exception of Zn, Cu (303.1 vs. 184 mg/kg DM), Fe (213.1 vs.187 mg/kg DM) and Mn (13.2
vs.7.5 mg/kg DM) were higher (P<0.05) in wet than dry season. In goats, season had no effect on
Cu (236 vs.274 mg/kg DM) and Fe (183 vs. 171 mg/kg DM), but had significant influence on Zn
(102 vs. 126 mg/kg DM) and Mn (13.6 vs. 6.8 mg/kg DM). The rib Ca (359 vs. 362 mg/g), P
(157 vs. 147 mg/g) and Mg (9.56 vs. 8.54 mg/g) contents of sheep was not influenced by season
and grazing area (P>0.05). However, goats rib Ca (360 vs. 326 mg/g), P (147 vs. 165 mg/g)
content was affected by season and grazing area (P<0.05), but Mg showed no seasonal variation.
The liver and rib bone of sheep and goats has demonstrated seasonal fluctuation in tissue mineral
reserve. Evaluation of specific minerals in different periods and body pools can be useful in the
diagnosis of mineral status of animals. With the exception of P which was marginal in all
seasons, mineral deficiencies were shown to affect animals more in the dry season. It can be
concluded that, sheep and goats would benefit from P, Cu, Zn and Mn supplementation,
particularly in the dry season
Key words: Minerals, liver and bone, sheep and goats, northern Kenya
C2041. EFFECTS OF SEED BORNE VIRUS INFECTIONS ON SELECTED POTATO
CULTIVARS IN KENYA
aGRO 2011 Biennial Conference 1*
Lung’aho, C., 2Chemining’wa, G.N., 2Shibairo, S.I2 and 2Hutchinson, M.J.
1
Kenya Agricultural Research Institute -Tigoni, P.O. Box 338-00219 Limuru, Kenya
University of Nairobi, Department of Plant Science and Crop Protection, P.O. Box 2905300625 Kangemi, Nairobi, Kenya
2
* Corresponding author:[email protected]
Abstract
Seed borne viruses are a major problem to seed and ware potato growers because they cause
yield depression and reduction in quality of tubers. The effects of seed borne virus infections in
34 potato cultivars selected from the Kenyan potato germplasm collection were determined by
comparing the yield performance of plants grown from virus infected seed with those grown
from virus free seed during the 2007 short rains and 2008 long rains seasons. The treatments
were laid out in a randomized complete block design (RCBD) with a factorial arrangement and
replicated three times. Total yield was reduced by between 52.9 and 89.6% in 2007 and by
between 47.4 and 90.2% in 2008 due to seed borne virus infections. In 2007, ware yield was
reduced by 100% in 25 of the cultivars while in 2008, 24 cultivars had their proportion of ware
yield reduced by 100% due to seed borne virus infections. Plants grown from virus infected seed
produced between 3.0 and 6.3 tubers per plant in 2007 and between 2.3 and 7.3 tubers per plant
in 2008. Plants grown from healthy seed tubers had between 6.0 and 14.0 tubers per plant in
2007 and between 5.7 and 14.3 tubers per plant in 2008. Reduction in tuber weights in 2007
ranged from 6.4 and 76.0% while the reduction in tuber weights varied between 10.2 and 77.4%.
This study demonstrated that seed borne virus infections significantly reduced total yield, ware
yield, seed yield, average tuber weight, and number of tubers per plant but the magnitude of the
reductions varied among the cultivars. Farmers can improve potato productivity by planting
disease-free seed tubers and minimizing current-season infections particularly where own saved
seed is preserved for use later.
Key words: Seed borne virus infections, potato, clean seed
aGRO 2011 Biennial Conference C2040. CASSAVA STARCH AS AN ALTERNATIVE LOW COST GELLING AGENT
FOR SLOW GROWTH IN VITRO CONSERVATION OF POTATO
1*
Lung’aho, C., 2Chemining’wa, G.N., 2Shibairo, S.I2 and 2Hutchinson, M.J.
1
Kenya Agricultural Research Institute -Tigoni, P.O. Box 338-00219 Limuru, Kenya
2
University of Nairobi, Department of Plant Science and Crop Protection, P.O. Box 2905300625 Kangemi, Nairobi, Kenya
* Corresponding author: [email protected]
Abstract
Lack of cost-effective protocols has hampered wide-scale application of slow growth in vitro
conservation of potato. Therefore, the potential of cassava starch as an alternative low cost
gelling agent for potato in vitro conservation media at normal propagation temperature was
investigated using a two factor experiment in a randomized complete block design for a period of
18 months. Three gelling agents: i) cassava starch (8%) + agar (0.25%), ii) cassava starch (8%)
and iii) agar (0.8%) were evaluated using three varieties (Arka, Dutch Robijn and Tigoni).
Plantlet survival and condition of plantlets after 18 months of conservation was comparable
when cassava (8%) + agar (0.25%) and agar (0.8%) were used as gelling agents for all the three
varieties and were higher than survival and condition of plantlets grown on media gelled with
cassava starch (8%) alone. Plantlets grown on media gelled with cassava starch (8%) + agar
(0.25%) and agar (0.8%) alone, respectively, had higher numbers of usable single node cuttings
per culture than plantlets grown on cassava starch (8%) regardless of the variety. Gelling costs
were reduced by 16.6 and 24.4 % when cassava (8%) + agar (0.25%) and cassava (8%) alone
were used, respectively, as the gelling agents compared to agar (8%) alone. However, media
gelled with cassava starch (8%) alone had poor clarity and gel strength indicating its unsuitability
for conservation. All plantlets that survived the 18-month conservation period had 100%
viability irrespective of the type of conservation media used that was used. Therefore, cassava
starch (8%) + agar (0.25%) may be used as a cheaper alternative for agar in potato conservation
media.
Key words: Cassava starch, gelling agent, in vitro conservation
C2042. EFFECT OF RATOONING ON GROWTH, LINT YIELD AND QUALITY OF
COTTON IN MWEA, KIRINYAGA SOUTH DISTRICT
aGRO 2011 Biennial Conference 1*
Macharia, J.M.K., Chemining’wa, G.N. and Kinama, J.M.
Department of Plant Science and Crop Protection, P. O. Box 29053, 00625, Nairobi
Abstract
Cultivation of ratoon cotton is becoming a common management practice in eastern and coastal
areas of Kenya, but its effects on lint yield and quality of cotton varieties in Kenya has not been
established. Field experiments were conducted in Mwea divison of Kirinyaga South District in
2008 short rains and 2009 long rains to evaluate the effect of cut-height on growth, pest
infestation, yield and quality of three cotton varieties. The treatments comprising cotton
varieties (HART89M, A540 and F962), cut-heights (5 cm, 10 cm, 15 cm above ground surface
and control- directly sown from seed) and N application levels (0 and 110 kg N ha -1), were laid
out in a randomized complete block design laid out as split-split plot arrangement. Ratoon plots
with cut-heights of 10 and 15 cm had significantly taller plants and higher number of stems/plant
than 5 cm cut-height ratoon plots and directly sown control plots. Ratoon crops with cut-heights
of 15 and 10 cm had significantly higher lint yield and percentage of grade ‘AR’ lint than 5 cm
cut-height ratoon and control plots. Nitrogen application had no effect on lint yield and quality.
Ratoon crops suffered early attacks by aphids, mites, mealybugs and stainers. Variety F962 had
higher lint percentage yield than the other varieties. Farmers can obtain better yields with ratoon
crops of 10 and 15 cm cut-heights than crops directly sown from seed, but ratooning cotton can
only be sustainable with appropriate pest management practices.
Key words: lint, quality, grade, pests, cut-height, variety, nitrogen
C2043. OCCURRENCE AND ABUNDANCE OF PLANT PARASITIC NEMATODES IN
CABBAGE-BASED CROPPING SYSTEMS IN KENYA
1*
Maina J. M., J.W. Waceke2 and G.M. Kariuki2
Department of Plant and Microbial Sciences, Kenyatta University, P.O. Box 43844-00100
Nairobi
2
Department of Agricultural Sciences and Technology, Kenyatta University, P.O. Box 4384400100 Nairobi
Abstract
A survey was conducted to determine the incidences of plant parasitic nematodes (PPN) and
factors enhancing population build-up in cabbage (Brassica oleracea L. var capitata)-based
cropping system in selected agro-ecological zones of Kenya. Samples were collected from sixty
cabbage growing farms in Nyandarua and Embu Counties. Nematodes assay was conducted for
both root and soil samples. Extraction of PPN from soil and root sample was done using
modified extraction tray method and modified maceration extraction technique respectively.
Extracted nematodes were enumerated, identified to genus level and their frequencies of
occurrence and population density determined. Plant parasitic nematodes belonging to various
genera were found associated with cabbage in six agro-ecological zones. The study revealed that
cabbage is a preferable host to lesion nematodes (Pratylenchus spp.) with 87% and 58%
frequency of occurrence in soil and roots, respectively. The mean population of this nematode
was 41/100cm3 of soil and 16.38/10g of roots. Root-knot nematodes were present at low
frequency (42% and 23% in soil and roots) and density (6.36/100cm3 of soil and 1.1/10g roots).
Helicotylenchus spp. were recovered in significant numbers in 82% frequency of occurrence in
rhizosphere and 27% in roots and a density of 26.28/100cm3 soil and less than 1 nematode per
10g of roots. Tylenchorhynchus spp. occurred in 67% of the soil samples (11.94/100cm3 soil)
while Paratrichodorus spp., Trichodorus., and Paratylenchus spp. were present in 78%, 57%
and 58% frequency of occurrence in the cabbage rhizosphere but at a low population density.
Other PPN detected in low frequencies of occurrence and density include; Tylenchus spp.,
Scutellonema spp., Heterodera spp., Xiphinema spp. among others. The study encourages more
research work to establish the economic importance of the reported nematode pests.
Keywords: agro-ecological zones, Brassica oleracea, Pratylenchus spp.
C2045. GENETIC DIVERSITY AND PATTERNS OF RELATIONSHIPS IN KENYAN
SORGHUM LANDRACES AS ASSESSED BY SIMPLE SEQUENCE REPEAT
MARKERS
Kisilu Maswili, R1, 3., Ngugi, K1 and Kiambi, D. 2
University of Nairobi, P.O Box 30197 00100, Nairobi.
2
International Crops Research Institute for the Semi-Arid Tropics, P.O Box 30709-00100,
Nairobi.
3
Kenya Agricultural Research Institute- Katumani, P.O Box 340-90100 Machakos
Abstract
Lack of genetic diversity data for Kenyan sorghum germplasm makes it difficult to manage and
utilize its genetic resources. The main objective of this study was to assess the extent and
structure of variability in sorghum landraces from Kenya using Simple Sequence Repeat (SSR)
markers. Genotypic data was used to characterize genetic diversity in 148 sorghum accessions
from western, Turkana, coast and eastern regions of Kenya. The accessions were genotyped as
bulks using 39 SSR markers. The procedures used were DNA extraction, DNA amplification
(PCR) and capillary electrophoresis. Average PIC value of 0.536 was observed indicating high
levels of polymorphism. Gene diversity index range was 0.03 – 0.91 with a mean of 0.57 per
locus. A total of 349 alleles were observed with an average of 8.9 alleles per locus. The average
heterozygosity level per locus was low at 0.237. Analysis of molecular variance showed all
variation components to be highly significant (P<0.001). The variability within accessions
among the populations was 56.4%, within individual accessions was 38.85% and among
geographical origins was 4.8%. A low level of genetic differentiation (FST = 0.048), a high
inbreeding level (FIS = 0.59), and a high value of heterozygozity deficiency (FIT= 0.61) were
observed showing an increased degree of allele fixation. Breeders’ and western material had the
highest diversity (6.48 and 6.28 alleles/accession respectively). Turkana sorghum diversity was
lowest (4.44 alleles/accession). Cluster analysis grouped the accessions into three groups with a
genetic distance (GD) range of 0.4 to 0.8. Results show a high diversity among Kenyan sorghum
germplasm that can be used in future crop improvement. However the different populations have
a closely related genetic background. There is need for a broader characterization including
molecular mapping; many loci are linked to important traits.
Keywords: Genetic diversity, Germplasm, Genotypic, Sorghum, SSR
C2116. THE INFLUENCE OF SOIL MOISTURE STORAGE ON MAIZE YIELD
UNDER DIFFERENT CONSERVATION TREATMENTS: THE LONGONOT CASE
STUDY, KENYA
*Mburu D.M, Lenga F.K and Wamocho, L.S
Jomo Kenyatta University of Agriculture and Technology. P.O Box 62000-00200, NAIROBI
aGRO 2011 Biennial Conference * Corresponding author. Email: [email protected]
Abstract
Inadequate soil moisture is a major constraint to agricultural development in the arid and semiarid areas. Soil conservation measures enhance soil moisture storage for increased crop yield.
Assessment of four soil conservation treatments that included terrace, hedgerow, grass strip and
tied ridging was carried out at Longonot for two years between 2003 and 2004. Short maturity
maize variety DH02 was used as the test crop to evaluate the treatment effects on maize yield for
two long rain and two short rain seasons. Soil moisture at different depths was determined with
neutron probe at 14 day intervals. Soil sampling for laboratory analysis (water content and
chemical characteristics) was done at the time of field soil moisture determination. Grain yield
was determined at crop maturity. There was no grain harvest in both short rain seasons due to
inadequate rain but there was grain the long rain seasons. Maize yield was highest where there
were tied ridges. The grain yield was 3000 kg/ha and 700 kg/ha during the long rain seasons in
2003 and 2004, respectively. Maize yield was comparable where terrace, hedgerow and grass
strip conservation methods were used; with an average of 1700 kg/ha and 450 kg/ha in 2003 and
2004, respectively. Tied ridging is a promising soil conservation technology in Longonot area
and it can increase soil moisture storage for food production.
Key words: Maize yield, moisture storage, semi-arid, Kenya
C2048. INTEGRATED MANAGEMENT OF GROUNDNUT ROSETTE DISEASE
1
* Mburu M.W.K., 2C. N. Karanja., 1R. D. Narla and 1F. M. Olubayo
1
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 29053,
Nairobi, Kenya.
2
Ministry of Agriculture, Nyandarua South District.
aGRO 2011 Biennial Conference * Corresponding author: [email protected]; [email protected].
Abstract
The ground rosette virus disease (GRD) is the most devastating disease of groundnuts and it is
transmitted by aphids. Identification of methods of controlling the disease would improve
groundnut productivity. A researcher managed field study was conducted in Siaya and Teso
districts of Kenya (March-May 2007) for one season to assess the effects of management
practices on aphid population and groundnut rosette disease (GRD) incidence on three groundnut
varieties (ICGV-SM 90704, ICGV-12991, JL-24). Disease management strategies assessed
included host resistance, trap crops, application of insecticide and rouging. The experimental
design was randomized complete block design laid out as split plot and replicated thrice. Disease
management strategies were allocated to main plots and varieties to subplots. Data on aphid
population and GRD incidence was collected every two weeks and yield at the end of the season.
Pesticide spray reduced aphid population and GRD incidence by 95% and 90%, respectively,
compared to 55-73% and 51-72% where trap crops were used. Rouging infected plants reduced
aphids and GRD incidence by 36% and 37%, respectively. Groundnut grain yield was highest
and comparable where pesticides and trap crops were used but lowest where rouging (42%) and
no control measures (28%) were applied. Groundnut varieties ICGV-SM 90704 and ICGV12991 showed resistance to GRD. The highest yields were obtained from the varieties when
aphid control measures were taken. Integrated management of GRD that combines host plant
resistance and pest control increases yields and marginal returns.
Key words: Groundnut rosette disease, host resistance, marginal returns.
C2051. EFFECT OF CHEMICAL FERTILIZERS, FARM -YARD AND POULTRY
MANURE ON GROWTH AND YIELD OF AMARANTHUS AND AFRICAN
NIGHTSHADE IN TAITA DISTRICT
1
Mnyambo J., 1S.I. Shibairo., 1F.M. Olubayo., 1A.W.Mwang’ombe and E. Lenihan2,
1
University of Nairobi, Department of Plant Science and Crop Protection, P.O Box 29053,00625, Nairobi, Kenya
2
University of Cork, Ireland.
aGRO 2011 Biennial Conference Abstract
African indigenous leafy vegetables (AILV’s) are known for their importance in providing
vitamins and minerals, and are largely grown by small scale farmers. They also play a crucial
role in income generation and subsistence. However, their production does not meet the
increasing demand. Studies were carried out in farmers’ fields in Taita district, to evaluate the
effect of chemical fertilizers, farm-yard and poultry manure on growth and yield of Amaranthus
(Amaranthus hybridus) and African nightshade (Solanum scabrum). The study was carried out in
four successive plantings where farm-yard manure at rates of 20 t/ha, 40 t/ha, 60 t/ha, poultry
manure at rate of 40 t/ha, farm yard manure at 20 t/ha, 40 t/ha, 60 t/ha each top dressed with
CAN at 1.03 t/ha, DAP at 0.2 t/ha top dressed with CAN at 1.03t/ha, farmer practice and a
control were evaluated. Results obtained revealed that, incorporation of farm-yard manure (20,
40, 60 t/ha), poultry manure (40 t/ha) and inorganic nitrogen (N), significantly increased plant
growth parameters (plant height, canopy width, number of branches, stem diameter) and hence
the yields. There was a significant difference (p<0.05) in all growth parameters among
treatments. The growth parameters of the vegetables were observed to be higher in plants grown
with organic manures and top dressed with inorganic N compared to those from plants grown
with the manures alone. There was a significant difference in yields of the vegetables among
treatments. The highest yields of 58 t/ha and 72 t/ha in Amaranthus and African nightshade
respectively were obtained from treatments with 60 t/ha cattle manure top dressed with
1.03kg/ha. The results indicated that adequate soil nutritional supply increases yield of these
vegetables thus providing an opportunity for improved health and nutritional status, dietary
diversity, food security status, incomes and livelihoods of poor rural and urban dwellers.
Key words: African indigenous vegetables, dietary diversity, manures, livelihoods.
C2053. EFFECTS OF COMBINED FOLIAR APPLICATION OF GIBBERELLIC ACID
AND BENZYLAMINOPURINE ON POTATO TUBER SPROUTING AND
SUBSEQUENT YIELDS
1
1
2
Muchiri Daniel P. M.,2 Nyankanga R.O., 2Hutchinson M.J. and 2Ambuko J.
Wambugu Agricultural Training Centre, , P.O. Box 5069-10100, Nyeri,
Department of Plant Science and Crop Protection, University of Nairobi, P.O.Box 2905300625, Kangemi, Nairobi
aGRO 2011 Biennial Conference Corresponding author: [email protected]
Abstract
Timely availability of well-sprouted seed potato tubers at the on-set of rains is critical for
attaining high yields. In the major potato regions in Kenya with a bimodal rainfall, the window
of planting is two weeks. However, most potato varieties are dormant for longer than three
weeks. Consequently, seed tubers planted too soon after their harvest exhibit delayed plant
emergence, poor establishment and produce low yields. Therefore, rapid tuber dormancy
breakage is desirable for tubers meant for seed. Gibberellic acid (GA) and benzylaminopurine
(BA) are known to cause dormancy breakage but little information is available on their combined
application. A field experiment was undertaken to determine the effects of combined application
of GA and BA on tuber sprouting and subsequent yields of Asante, Dutch Robyjn and Kenya
Sifa potato varieties. Foliar application of GA and BA was done alone or in combination at four
levels; 0, 50,100 and 300ppm for GA and 0, 50, 75 and100 ppm for BA. There was no
significant difference between GA when applied singly or in combination with BA on dormancy
breakage but there was significant effects of combined application of GA and BA on tuber sprout
length, number of sprouts per tuber and sprouts vigour in a dose dependent manner. In the field,
tubers from GA and GA+BA treated plants gave plants with more stems per plant, leaflets per
plant, number of tubers per plant and total yields at harvest with increased rate of application.
BA alone was not effective on breaking dormancy. The results from this study show that GA and
BA work synergistically to initiate dormancy breakage and sprouts growth. Therefore, foliar
application of GA alone or in combination with BA can be used to break dormancy in tuber
potatoes and improve the subsequent sprout growth and tuber yields.
Key words: Gibberellic acid, Benzylaminopurine, Potato, Tuber sprouting, Dormancy
C2056. EFFECTS OF AUXIN-DOSE AND SPRAY-INTERVAL ON SUCKER
DEVELOPMENT IN ROSE (Rosa hybrida L.)
1
Musembi, N. N., N. Adeya2 and W.W. Murigi1
1
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 30197 –
00100, Nairobi, Kenya.
2
Department of Seed, Crop and Horticultural Science, School of Agriculture and Biotechnology,
Moi University, P.O. Box 1125 - 30100 Eldoret, Kenya.
This study aimed at investigating effects of auxin spray on sucker development in roses. The
rationale was to develop technology for prevention or minimization of sucker development in
production of commercially acceptable rose cut flowers. Different doses (0, 15, 30, 45 and 60
mg/L) of auxin, naphthalene acetic acid (NAA) (Anatone®, a commercial auxin) and a hand
desuckered positive control were applied in commercial greenhouse (Buds and Blooms Ltd Nakuru County of Kenya) of roses grown on substrate (pumice). Treatments were laid out in a
randomized complete block design (RCBD), with the location within the greenhouse as the
blocking factor. Data were subjected to analysis of variance (ANOVA) and means were
separated using Tukey’s Honestly Significant Difference (HSD). The interaction effect of auxin
dose × spray interval significantly (P < 0.001) influenced the number and growth rate of suckers
in a shoot. All auxin doses completely prevented sucker development on rose shoots, from budbreak to harvestable stem stage of shoot growth. However, auxin dose × spray interval
significantly influenced the occurrence of leaf epinasty, a physiological condition with negative
impact on cut shoot foliage quality. Leaf epinasty affected: 22.5%, and 5% of the fully grown
rose stems treated with 15 mg/L NAA with spray interval of 1 d, and 6 d, respectively.
Occurrence of bullheads, another physiological condition was found to be significantly
influenced by auxin dose.
This desuckering technology is expected to lower rose production
costs. Modes of action are discussed.
Keywords (5): Roses, Rosa hybrida, chemical-desuckering, auxin, Napthalene-acetic-acid,
C2123. CULTIVAR REACTION TO ANTHRACNOSE (Colletotrichum gloeosporioides)
AND POST-HARVEST MANAGEMENT OF THE DISEASE IN AVOCADO
Mutembeia M. M., Kimenjub J.W. and Narlab R. D
a
Ministry of Agriculture P. O Box 66730-00800 Nairobi;
b,
University of Nairobi, Department of Plant Science and Crop Protection, P. O Box 2905300625 Nairobi Kenya
Abstract
aGRO 2011 Biennial Conference Anthracnose is a serious postharvest disease in avocado causing losses in both quality and
quantity. A study was conducted to screen commonly grown avocado cultivars for susceptibility
to anthracnose and evaluate possible methods of reducing postharvest losses due to this disease.
Four commonly grown avocado cultivars, Fuerte, Hass, Pinkerton and Puebla were screened for
cultivar susceptibility to anthracnose. Both mature and almost mature fruits were used in order to
establish the effect of maturity on fruit susceptibility to the pathogen. A total of 18 mature and 18
almost mature fruits were used for each variety. They were then artificially inoculated with
conidial suspensions of Colletotrichum gloeosporioides. The most susceptible cultivar was used
to investigate the efficacy of three fungicides; methyl thiophanate, fenhexamid, iprodione and
hot water in reducing avocado post-harvest fruit rot due to anthracnose. The four cultivars were
susceptible to the disease with varying degrees of susceptibility. Cultivar Fuerte was the most
susceptible with a mean surface necrosis (SN) diameter of 4.0cm for the mature fruits while
cultivar Hass was the least susceptible with a mean surface necrosis diameter of 2.5cm. Methyl
thiophanate showed significant reduction of disease progression with a mean SN diameter of
1.3cm compared to iprodione (3.1cm), fenhexamid (3.3cm) and hot water (3.3cm). Cultivar
Fuerte was highly susceptible to anthracnose. Methyl thiophanate was therefore considered to be
a possible fungicide for post-harvest management of anthracnose fruit rot in avocado and can be
further evaluated for this purpose alongside other methods.
Key words: Avocado, anthracnose, heat treatment, methyl thiophanate, post-harvest
C2059. INTEGRATED MANAGEMENT OF APHID-TRANSMITTED VIRUSES IN
POTATO (Solanum Tuberosum L.)
1
Muthomi, J.W, 1Muinde, E.M., 1Nderitu J.H.,1Olubayo F.M., 2Kabira, J. N. and
1
Chemining’wa, G. N.
1
Department of Plant Science and Crop Protection, University of Nairobi.
National Potato Research Centre, Kenya Agricultural Research Institute
P. O. Box 30197, 00100, Nairobi, Kenya
2
*Corresponding author e-mail: [email protected]
Abstract
Potato aphids and aphid transmitted viruses are major constraints to seed potato production in
Kenya. Studies were carried out to evaluate the effectiveness of combining border crops, mineral
aGRO 2011 Biennial Conference oil and bifenthrin (Brigade®) in the management of potato aphids and associated virus diseases.
Field experiments were conducted at Tigoni and Kabete over two seasons. Potato plots were
surrounded by maize borders and aphid infestation was controlled by spraying either the potato
crop, maize borders or both with bifenthrin and mineral oil, singly or in combination. Data
collected included aphid population, virus disease incidence and potato yield. Mineral oil and
bifenthrin treated plots significantly (P≤0.05) reduced aphid population by up to 96% and virus
titre on potato tubers by up to 78.5% as compared to control plots. Lowest mean aphid
population of 0.2 was recorded in plots where mineral oil was applied on potatoes while plots
without maize borders had the highest mean aphid population of 5.4 per 30 leaves. Tuber yields
were not significantly different among treatments. The study demonstrated that integrating
border crops, insecticides and mineral oil is beneficial in the management of potato aphids and
associated viruses in seed potato production. Further trials should be carried out to determine the
application rate and frequency of mineral oil and bifenthrin, which can control viruses at
minimum cost with maximum returns to farmers.
Key words: Aphids, bifenthrin, border crops, mineral oil, potato viruses
C2059. MANAGEMENT OF THRIPS IN BULB ONIONS USING VEGETABLE INTERCROPS
* Muthomi J. W.., S.M. Gachu, R.D. Narla., J.H. Nderitu and F.M. Olubayo
Department of Plant Science and Crop protection, Faculty of Agriculture, University of
Nairobi, P. O. Box 29053, 00625, Kangemi, Nairobi, Kenya.
Abstract
Field experiments were conducted between July 2008 and May 2009 to determine the
effectiveness of intercropping in the management of thrips (Thrips tabaci) on bulb onion. Three
onion varieties (Bombay red, red Creole and orient F1) were intercropped with carrot (Daucus
carota), spider plant (Cleome gynandra) and French beans (Phaseolus vulgaris). The
experimental design was randomized complete block design laid down as a split plot and
aGRO 2011 Biennial Conference replicated four times. Thrip population was determined by destructive sampling of onions after
every two weeks. Thrips damage incidence and severity was determined on a weekly basis and
damage severity was estimated on a scale of 1-5. The efficacy of vegetable intercrops in the
management of thrips was compared with an insecticide (Imidacloprid). Intercropping onion
with spider plant significantly reduced thrips population by up to 45.2% and 21.6% respectively
but the effect of French beans was not significant. Intercropping onion with spider plant, carrot
and French beans significantly reduced thrips damage severity with spider plant having the
highest reduction of up to 15.7% but their effect on damage was not significant. The study
therefore shows that Spider plant, French beans and carrot can be utilized in the management of
onion thrips but further investigations should be undertaken on their optimal spatial arrangement
in an intercropping condition to prevent their effect on bulb yield.
Key words: Allium cepa, Cleome gynandra, Daucus carota, Phaseolus vulgaris, Thrips tabaci.
C2063. RESPONSE OF SWEET POTATO VARIETIES FOR WHITE FLIES
RESISTANCE
1
*Muturi P. W. 1., M.W.K. Mburu1., J.K. Mwololo 2., E.M. Ateka3., R.W. Njeru 1 and K.
Njoroge
1
Pwani University College
3
Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology
2
*Corresponding Author: [email protected]
Abstract
Sweet potato is an important food security crop in Kenya. The main sweet potato producing
areas in Kenya include Nyanza (52 %), Western (35 %), Eastern (6 %), Rift valley (4 %), Central
(2 %), and Coast (2%) provinces. Insect pests and diseases are among the major biotic
aGRO 2011 Biennial Conference constraints to sustainable sweet potato production. Whitefly (Bemisia tabaci) is a vector of sweet
potato chlorotic stunt virus which jointly with the sweet potato feathery mottle virus cause sweet
potato virus disease (SPVD), a devastating disease of sweet potato. Sweet potato plant resistance
to whitefly would provide a cheap way to minimize viral infection in this crop. The objective of
this study was to evaluate white fly populations in several sweet potato varieties. Twenty
varieties comprising of improved and landraces were established at Kabete, Juja and Kibirigwi in
Central Kenya. The trial was laid out in randomised complete blocks replicated thrice. They were
counted on five top, middle and lower leaves on each plant early in the morning when the insects
are less active.Adult whitefly populations were monitored on sweet potato leaves fortnightly.
Variation of whitefly population in season, site and variety interactions was highly significant at
P <0.001. Whitefly populations varied appreciably within each site over time and also among
seasons and sites. There was variety based variation in the whitefly population. Most of the
varieties that had high and low white fly populations had broad and narrow leaves, respectively.
Leaf size may be used as an indicator of resistance to SPVD in rapid variety screening trials.
Key words: Sweet potato, host plant resistance, leaf size
C2066. RESPONSE OF AFRICAN LEAFY VEGETABLE VARIANTS TO Meloidogyne
incognita
NCHORE, S.B1*; J.W, WACEKE2 AND G.M, KARIUKI2
1
Plant and Microbial Sciences Department, Kenyatta University, Kenya
2
Department of Agricultural Science and Technology, Kenyatta University
*Corresponding author email: [email protected]
Abstract
aGRO 2011 Biennial Conference Root-knot nematode (Meloidogyne spp.) severely damages vegetables in both nursery and field
establishments. Seven variants of African leafy vegetables (ALVs) [Svo (Solanum villosum
orange), Sng (S. nigrum green), Sp (S. nigrum purple), Ac (A. cruentus), Ad (A. dubius), Ah (A.
hypochondriacus), and Cgp (Cleome gynandra purple stemmed) were inoculated with M.
incognita under greenhouse conditions. A susceptible check (Tomato cv. Moneymaker)] was
included as a control. The experiment was laid-out in completely randomized block design with
four replications. Each variant was planted in a 12-cm-diameter plastic pot filled with 1 kg
autoclaved soil-sand (1:2) potting medium. Egg-masses of M. incognita were hand-picked from
pure culture of the nematode earlier raised on tomato. Ten egg-masses were placed around the
rhizosphere zone of each ALV/pot for comparison with un-inoculated control and susceptible
check. The experiment was terminated 75 days after inoculation and data on shoot height (SH),
fresh shoot and root weight, galling index (GI) and reproduction factor (Rf) collected. Reaction
to Meloidogyne incognita varied (P<0.05) among the ALVs ranging from very susceptible to
resistant with the highest GI of 3.75 in Sng and lowest GI of 0.5 in Ah relative to the check
(GI=5.0). Nematode Rf differed significantly (P<0.05) among the variants with Ah (Rf=0.9) and
Cgp (Rf=1.53) recording lowest values, while Sng recorded the highest score (7.69) compared to
the check (13.0). Meloidogyne incognita significantly reduced SH in Sng (17.0 %), Ac (13.4 %),
Ad (8.8 %), Svo (7.9 %), Ah (5.3 %), Snp (3.3 %), Cgp (2.5 %) relative to the check (18.0 %)
with heavy galling recorded in Sng and check. Based on GI and Rf it was concluded that Sng,
Snp and Svo were susceptible and good hosts, Ad was tolerant, Ah was poor host while Ac and
Cgp were fair hosts.
Key words: Amaranthus, Cleome, Solanum spp., root-knot, resistance, tolerance
A2070. EFFECTS OF ENZYMES AND PROBIOTICS ON GROWTH PERFORMANCE
AND GASTROINTESTINAL MORPHOLOGY IN BROILER CHICKEN.
1
1
2
Njeru Karimi, 1R. Wahome, 1Joyce Maina and 2P. Kuria
Department of Animal Production, CAVS, University of Nairobi.
Department of Veterinary Pathology.
Abstract
A study was done to investigate the effect of yeast culture (Diamond V XPC) and alloenzyme
(Allzyme SSF) on the performance and gut morphology in broiler chicken. One hundred and
aGRO 2011 Biennial Conference sixty broiler chicks were fed on diets formulated according to Kenya Bureau of Standards
(KeBS) specifications and supplemented with either alloenzyme (0.02%) or yeast culture. Four
treatment diets were formulated. Diet 1 was supplemented with yeast culture, Diet 2 both yeast
culture and alloenzyme, Diet 3 alloenzyme only and Diet 4 was the control diet and yeast culture
and enzymes were not added. The birds were slaughtered when they were 21 and 42 days old and
the lengths of rectum, caeca, ileum, duodenum, jejunum and the weights of the gizzard, liver and
bursa of Fabricius were recorded. Perfomance parameters such as feed intake, weight gain, body
weight, Feed Conversion Ratio (FCR) and Protein Efficiency Ratio (PER) were also recorded on
the 21st and d 42nd day of age. There were no significant effects (P > 0.05) of yeast culture on
growth performance and on gut morphology across treatments. However, birds fed on diets
supplemented with yeast culture had a trend of increased performance compared to the control
diet. Alloenzymes had no effects on broiler performance and gut morphology.
Key words: Broilers, Yeast culture, alloenzyme, performance, gut morphology,
C2072. INFLUENCE OF MANGO ROOTSTOCK ON PERFORMANCE OF IMPROVED
MANGO CULTIVARS IN THIKA
1
1
Njuguna J.K., 1Wanjala S., 1Wepukhulu, B. and 1Gatambia, E
Kenya Agricultural Reseach Institute, P.O Box 220, 01000 Thika Kenya
Correspnding author: [email protected] or [email protected]
Abstract
aGRO 2011 Biennial Conference Mango is one of the most widely grown fruit crops in the world. In Kenya, It is one of the most
important fruit crop in terms of area under cultivation, volume produced and value. However,
despite the importance of this crop, its potential in Kenya has not been fully exploited due to
constraints such as diseases, insect pest infestations, poor crop husbandry and usage of
inappropriate rootstocks among other factors. The two commonly used rootstocks in Kenya
namely Sabre and Peach were adopted from South Africa which is a subtropical country. Their
characteristics and their influence on improved cultivars under tropical conditions, as the case in
Kenya, have not been documented. A study was therefore initiated to determine the effect of the
two rootstocks on three improved cultivars namely Glenn, Irwin and Tommy Atkins. The trial
was laid out in RCBD. Data collected were number of fruits and fruit weight of the three
improved cultivars. The data were then subjected to ANOVA and mean separated using Student–
Newman-Keuls’ Multiple range test at 5 % level of significance. There was a significant
(P<0.05) difference between cultivars for fruit number and fruit weight. In addition, the
interaction effect of the rootstock and cultivar was significant. All the three cultivars produced
more and heavier fruits when grafted on Sabre rootstock than when grafted on peach rootstock.
Cultivar Tommy Atkins had the highest fruit number and weight followed by Irwin while Glenn
had the lowest. This could be attributed to faster and vigorous growth of cultivar Tommy Atkins
thus establishing a large canopy earlier than other cultivars. It can be concluded that Sabre is a
more superior rootstock than Peach and of the three cultivars evaluated, Tommy Atkins has the
greatest yield potential particularly when grafted on Sabre rootstock.
Keywords: Improved cultivars, Growth, yield characteristics, commercialization
A2073. EFFECTS OF SUBSTITUTING MAIZE WITH RICE-MILLING BY-PRODUCTS
IN COMMERCIAL LAYER CHICKEN DIETS.
1
1
Njuguna K.W. 2Kabuage, L.W. and 2Maina, J.G
Department of Livestock Production, P.O. Box 34188-00100 Hill, Plaza Nairobi.
2
University of Nairobi, College of Agriculture & Veterinary Medicine, Department of Animal
Production.
Abstract (A 2073)
aGRO 2011 Biennial Conference Inadequacy of high quality and reasonably priced poultry feeds constitute major challenges to the
development of a vibrant poultry industry. Maize and its by-products are the main energy
sources used in the manufacture of commercial poultry diets. Maize has an energy content of
3550 ME kcal/kg compared to the more abundant broken rice (BR), fine bran (FB) and coarse
rice with 2980, 2990 and 2650 ME kcal/kg respectively. Maize, the staple food for most Kenyans
is expensive and only limited quantities are available for feed manufacturing, hence the need to
explore cheap alternative energy sources. BR and FB are produced by the multi-step rice milling
process, while the single step milling process leads to the production of a single combined byproduct (SCB), all studied in this research. One hundred and forty ISA brown layer chickens
were distributed to five treatments in a completely randomized design. They were housed in
battery cages at the University of Nairobi Poultry Unit from onset of lay to the peak of the laying
cycle. Three test diets containing rice by products and two control diets constituted by a
commercial layer mash and a maize soya bean basal diet were evaluated. The test diets contained
60% BR during the first eight weeks and 40% over the subsequent eight week period; SCB
graded at 0, 5 and 10 %, while FB was fixed at 20%. Performance of birds on the diets
containing 40 % BR and graded with 5 and 10% SCB were significantly (P < 0.05) higher than
those on the two control diets (except for feed efficiency). Gross margins for birds on the two
test diets were higher by 39 shillings per bird than those on the control diets. Substitution of
maize with the rice-milling by-products up to 65 % was observed to be technically feasible and
profitable.
Key words: Maize, layer chicken, rice-by products, performance, gross margins
C2075. PLANT PARASITIC NEMATODES ASSOCIATED WITH COFFEE IN KENYA
Nzesya J.M., Kimenju J.W. Muiru W.M., Mutua, G.K. and Wachira, P.M.
Department of Plant Science and Crop Protection, University of Nairobi. P.O Box 29053-00625
NAIROBI
Abstract
This study was conducted with the aim of determining whether plant parasitic nematodes were
contributing to the decline in productivity of coffee. A survey was undertaken using a
questionnaire which was administered to 200 farms households and aimed at capturing;
aGRO 2011 Biennial Conference management practices in coffee, cultivars and soil characteristics at each sampling point. About
200 composite root and soil rhizospere samples were collected from coffee farms, (where the
questionnaires had been administered) selected at random in 11 districts located in the three
coffee zones namely; Tea-coffee (UM1), main coffee (UM2) and the marginal coffee (UM3)
zone including the regional research stations. Nematodes were extracted using modified
centrifugal floatation technique, identified to genus level and enumerated. Plant parasitic
nematodes belonging to 20 genera were recovered from the coffee rhizosphere. The dominant
nematodes detected were of the genera; Tylenchulus spp., Meloidogyne spp., Tylenchorhynchus,
Pratylenchus spp., Tylenchus spp, Rotylenchus spp, Hemicyclophora spp with an abundance of
167, 161.,160, 158.0, 156., 148, 139 juveniles/200 cm3 soil, respectively. Other plant
nematodes found in the coffee fields included: Helicotylenchus and Scutellonema spp.
Hoplolaimus, Hemicroconema, Criconema, Aphelenchoides, Trichodorus, Bunonema,
Radopholus, Paratrichodorus, Longidorus, Scutellonema and Xiphinema. In addition, free-living
nematodes (bacteriovores and fungivores as well as predaceous) belonging to 10 different genera
were also identified. A multivariate analysis showed that the population densities of plant
parasitic nematodes and composition nematode community varied significantly (P=0.01) among
coffee growing zones partly caused by the differences in farm management practices which
impacted on soil chemical properties such as pH, Na, P, K and Mn.
Key words: Agro-ecological zones, Meloidogyne spp., Pratylenchus spp,free living nematodes
C2076. COMBINING ABILITIES FOR GRAIN YIELD AND GREY LEAF SPOT
RESISTANCE IN MAIZE
*1
1
2
3
Nzuve, F.M., 2Githiri, S.M., 3Mukunya, D.M. and 4Gethi, J. 2011.
Makerere University, P O Box 7062, Kampala, Uganda.
Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62,000 - 00200 NAIROBI
Department of Plant Science and Crop Protection, P O Box 29053-00625, Nairobi
4
Kenya Agricultural research Institute, P O Box 340, Machakos
*
Maize is a very important staple crop which helps to avert hunger and famine in sub-Saharan
Africa. However, the current maize production does not meet the current consumption given the
increased global population. The grey leaf spot disease (GLS) threatens maize production. A full
diallel among seven inbred lines was made to identify maize lines with superior grain yield and
high GLS resistance. The single cross hybrids were grown in a randomized complete block
design in three replicates at three sites namely; Kenya Agricultural Research Institute (KARI),
Kiboko and Kakamega; and at the University of Nairobi, Upper Kabete Campus, Field station.
There was natural GLS infection at KARI, Kakamega whereas artificial inoculation was used at
the Upper Kabete field station. The data on grain yield, grey leaf spot disease and other
agronomic traits was analysed following the Griffing’s method one model one of the SAS
program to obtain the general combining ability (GCA) and specific combining ability (SCA).
The inbred lines showed significant variation in reference to their GCA and SCA effects. The
inbred lines, CML 384 and CML 373 were the best combiners for grain yield with GCA effects
of 0.79 and 0.56 respectively while TZMI 711 and CML 373 were the most GLS resistant
parents with GCA values of -0.51 and -0.398 respectively. The local maize breeders could now
incorporate into recurrent and back cross recovery programs the genes for GLS resistance in
CML 373 and TZMI 711 and the grain yield genes in CML 384 to help bridge the gap between
researchers’ and farmers’ field maize yield. This will ensure food and nutritional security
especially in sub Saharan Africa which is faced with chronic malnutrition and famine.
Key words: Maize, Grey leaf spot, GCA, SCA, Grain yield,
C2077. APPLICATION OF LOW COST TISSUE CULTURE TECHNOLOGY IN
SWEET POTATO (IPOMOEA BATATAS (L) LAM) REGENERATION
Ogero K.O1*, Gitonga N.M3, Mwangi M1, Ombori O.2 and Ngugi M.2
1
Department of Agricultural Science and Technology, Kenyatta University, P.O. Box 4384400100, Nairobi
2
Department of Plant and Microbial Sciences, Kenyatta University
3
Department of Agriculture, Meru University College of Science and Technology, P.O. Box, 972
- 60200, Meru, Kenya.
*Corresponding: [email protected]
Abstract
aGRO 2011 Biennial Conference Sweet potato production in Eastern Africa has been declining due to lack of quality and clean
planting materials. For many years now, tissue culture technology has boosted the establishment
of quality seed systems for vegetatively-propagated crops. Developing countries have not
maximized the benefits of in vitro plant regeneration due to the high costs incurred during the
process. The aim of this research was to reduce the cost of sweet potato tissue culture nutrients
by using alternative nutrient sources that are locally available and cheaper than the conventional
MS salts. The conventional sources of MS salts were substituted with a foliar feed available
locally and containing both macro- and micronutrients (27:10:16 (N: P: K) + microelements). 2
grams of this was used in the preparation of one litre of medium. This was supplemented with 30
g/l of table sugar and 9 g/l of agar. MS medium supplemented with 30 g/l of table sugar and 3 g/l
of gelrite was used as the control. Two farmer-preferred sweet potato varieties, KEMB 36 and
Tainurey were initiated on the low cost medium and on the conventional MS medium. The mean
number of nodes, leaves, roots and plant heights were determined and comparisons made
between the two media. 96.2% reduction in terms of nutrient cost was achieved. There was a
significant difference in the number of nodes produced by KEMB 36 on the two media with
plantlets cultured on the low cost medium producing 4 nodes per plantlet while those cultured on
the conventional MS medium had an average of 5 nodes per plantlet. No significant differences
were recorded in the number of nodes produced by Tainurey on the two media. This indicates
that the developed low cost medium can be adopted efficiently in sweet potato micropropagation
thus availing disease-free plantlets at reasonable a cost.
Key words: Planting materials, seed systems, tissue culture, low cost medium, sweet potato, in
vitro plant regeneration
C2078. COST-EFFICIENT NUTRIENT SOURCES FOR TISSUE CULTURE OF
CASSAVA (Manihot esculenta CRANTZ)
Ogero K.O1*, Gitonga N.M3, Mwangi M1, Ombori O.2 and Ngugi M.2
1
Department of Agricultural Science and Technology, Kenyatta University, P.O. Box 4384400100, Nairobi, Kenya.
2
Department of Plant and Microbial Sciences, Kenyatta University.
3
Department of Agriculture, Meru University College of Science and Technology, P.O. Box, 972
- 60200, Meru, Kenya
*Corresponding: [email protected]
Abstract
Tissue culture technology has been utilized in many countries in the production of disease-free
planting materials for many crops including cassava. The application of this technology to a wide
aGRO 2011 Biennial Conference array of crops is, however, constrained by high costs associated with it. The objective of this
study was to evaluate the possibility of using locally available salts and fertilizers as alternative
nutrient sources for cassava tissue culture. A low cost medium for cassava micropropagation was
developed. The conventional sources of four Murashige and Skoog (MS) macronutrients
(potassium dihydrogen phosphate, potassium nitrate, ammonium nitrate and magnesium
sulphate) were replaced with locally available fertilizers. A solid foliar fertilizer containing all
the micronutrients was used as their alternative source. The conventional MS medium was used
as the control. Both media were supplemented with 30 g/l of table sugar and 3 g/l of gelrite. Two
cassava varieties, Muchericheri and KME1 were regenerated on the two media. The regeneration
indices for both varieties on the two media were determined and compared. The cost of culture
nutrients was reduced by 95.5% when the alternative nutrient sources were used indicating that
this strategy can greatly boost affordability of healthy cassava seedlings. The two cassava
varieties had the same regeneration index on the low cost medium with each having a mean of 4
nodes per plantlet. However, on the conventional medium Muchericheri had a significantly
higher regeneration index than KME1 having produced 6 nodes per plantlet compared to KME 1
which had 5 nodes per plantlet. This indicates that the developed low cost medium can be
applied to a wide scope of cassava cultivars unlike MS medium which had genotype-dependent
regeneration efficiency. The regeneration indices of four nodes per plantlet on the low cost
medium are within the accepted limit of 3-7 nodes per plantlet.
Key words: Cassava, nutrient sources, low cost medium, regeneration index
C2080. EFFECT OF pH ON SUITABILITY OF SUBSTRATES FOR
MUSHROOM (Pleurotus ostreatus) CULTIVATION
OYSTER
Odero G.M. Mutitu, E.W. Kimenju J.W., Maina, W.M. and Wachira, P.M.
Department of Plant Science and Crop Protection, University of Nairobi. P.O Box 29053-00625,
NAIROBI
Abstract
Pleurotus ostreatus (Fr.) Kummer is a primary decomposer that can be grown on many readily
available lignocellulosic materials. However, pH of the substrate is one of the key factors that
affect its mycelial growth and subsequently the sporophore yields. This study was undertaken to
determine the effect of varying pH on growth parameters of P. ostreatus cultivated on maize
cobs (Zea mays), coconut fibre (Cocos nucifera), sugarcane bagasse (Saccharum officinarum)
aGRO 2011 Biennial Conference and sawdust (Eucalyptus sp). To do this, pH of 6.0, 6.5 and 7.0 were chosen as treatments. The
results indicated that pH had significant effect (P≤0.05) on yield, average biological efficiency
(ABE), number of pileus, days to pinning and flushing interval among all the four substrates
tested. The average biological efficiency of maize cobs increased from 18.4% to 68.3% when the
pH was adjusted to 6.5. However, the efficiency decreased to 31.8% when the pH was raised to
7.0. Coconut fiber recorded the shortest duration to pinning and a 5 times increase in ABE when
pH was adjusted to 6.0. Among the substrates tested, sawdust recorded more than 10 times
increase in ABE at pH 7.0. Sugarcane bagasse recorded the shortest duration to pinning and a 3
times increase in ABE at pH 6.5. The fresh mushroom yields increased by between 1.7 to 10.9
times in maize cobs and sawdust respectively. During the crop’s cycle, no mushroom bags were
lost through contamination at pH higher than 6.0.
Key words;
Average biological efficiency, mycelia, pinning, primodia,
C2082. RESPONSE OF CANNING NAVY BEAN TO APPLICATION OF FERTILIZERS
AND PESTICIDES
1*
Ogutu, P.O., Chemining’wa, G.N. , J.H. Nderitu and Kinama, J. M.
University of Nairobi, Department of Plant Science and Crop Protection, P. O. Box 29053,
00625, Nairobi
*
Abstract
Low soil fertility, insect pests and diseases are the major constraints to improvement of canning
navy bean productivity in Kenya. A study was conducted at the University of Nairobi’s Kabete
Field Station during 2010 short and long rains to determine the effect of fertilizers and pesticides
on growth, yield and quality of canning navy beans. The fertilizer treatments were full dose
farmyard manure (8 tonnes/ha), half dose farmyard manure (4 t/ha) + half dose NPK (100 kg/ha),
Full dose NPK (200 kg/ha), Rhizobium inoculation, control (no fertilizer) while the pesticide
aGRO 2011 Biennial Conference treatments were fungicide spray (Ortiva), insecticide spray (Actara), fungicide spray (Ortiva)
plus pesticide spray (Actara) and Control (No spray). The experimental design was a randomized
complete block design laid out in a split plot arrangement with three replications. The variety
used was Mexican 142. Results demonstrated that pesticide sprayed and fertilizer supplied plots
had significantly(p≤0.05) higher plant count than non-treated control plots Organic fertilizers
significantly (p≤0.05) increased the number of nodules but pesticide application had no effect.
Pesticide application significantly ((p≤0.05) improved grain yield and quality only in fertilizer
supplied plots, while fertilizer treatments had no yield-effect in unsprayed crops. Partial cost
analysis demonstrated that application of half dose farmyard manure (4 t/ha) plus half dose NPK
(100 Kg/ha) in combination with insecticide or insecticide+fungicide sprays was the most costeffective treatment regime. Pesticide sprays, Rhizobium inoculation and combined moderate
doses of organic and inorganic fertilizers have the potential to improve navy bean productivity.
Key words: Nodule, navy bean, fungicide, insecticides, cost, farmyard, NPK
C2083. FARMER-FRIENDLY STRATEGIES OF MANAGING WEEDS IN CARROTS
(Daucus carota L.)
1
Ojowi D.O, 1 Ariga E.S, 1 Michieka R.W, and 1Kimenju J.W.
1
Department of Plant Science and Crop Protection, University of Nairobi, Kenya, P. O. Box
29053, 00625, Nairobi
Abstract
Weed control constitutes one of the main cost items in carrot production. Field study was
conducted at the field station farm, University of Nairobi in 2010 period with the aim of
developing a cost-effective strategy of managing weeds and increasing the competitive ability of
the crop against weeds. The weed control strategies tested were; black plastic mulch, grass
mulch, herbicides (Linuron and oxyfluorfen), mulch / herbicide combinations, foliar feed
fertilizer/ one hand weeding combinations, foliar feed fertilizer / 1.5 cm grass mulch
combination, hand weeding every two weeks, famers practice (two hand weeding), and control
aGRO 2011 Biennial Conference (no weeding). Pigweed (Amaranthus hybridus), black jack (Bidens pilosa) and oxalis (Oxalis
latifolia) were the most common weeds in the experimental plots. For instance the occurrence of
pig weed in a quadrant was 67 % compared to oxalis 16%, black jack 7%, yellow nutsedge 8%,
and chick weed 3%. The efficacy of weed control was significantly (P ≤ 0.05) different among
the methods tested. Black polythene was the most effective method with 99.2 % weed control
compared 78% in plots treated with a herbicide (Linuron), which is at par with 19 % two hand
weeding (farmers practice) .Carrot yield was (33984 kg/ha) in plots where weeds were controlled
using black polythene compared to (26544kg/ha) and (14168 kg/ha) under the herbicide and
farmer practice, respectively. Application of foliar feed fertilizer increased tolerance in the crop
against the effect of weed competition. It was concluded that mulching is an effective strategy of
reducing weed growth in carrots. Foliar feed application imparts competitive ability in the crop
against weeds.
Key words: Herbicide, mulching materials, foliar feed fertilizer, weed control efficiency, yield
components
C2085. INSECT SPECIES ASSOSIATED WITH AFRICAN INDIGENOUS LEAFY
VEGETABLES (Amaranthus hybridus and Solanum scabrum) IN TAITA DISTRICT,
KENYA
Olubayo, F.1, Mnyambo, J., 1 Shibairo, S., 1 Mwang’ombe, A. 1 and Lenihan, E. 2
1
University of Nairobi, Department of Plant Science and Crop Protection,
2
University of Cork, Ireland
Abstract
The African Indigenous Leafy Vegetables (AILV’s) form a substantial proportion of the diets of
most Kenyans. They are known to have a good yield potential and ability to address food
insecurity and nutritional problems among the rural populations. However, the production of
AILV’s has been faced with constraints, among them insect pests infestation which cause
considerable yield losses. To establish the range of insect pests constraining production of
AILV’s at the Kenyan Coast, a study was conducted in Taita district. The study covered four
aGRO 2011 Biennial Conference successive plantings between May 2008 and March 2009, aiming at documenting the insect pests
associated with the major AILV’s (Amaranthus hybridus and Solanum scabrum). In addition, the
study sought to delineate the most economically important insect pests and development of
control measures. In the farmers’ fields, seedlings were planted in plots of 3mx3m under
completely randomized blocks. To quantify the insect pests, three leaves were sampled from ten
randomly selected plants for twelve weeks after transplanting. The insect species counts were
identified using entomological identification keys, diagrams in books and by comparison with
insect collections preserved in the Entomology laboratory of Kabete Campus, University of
Nairobi. Twelve insect species belonging to six insect orders infested the AILV’s in all the four
plantings. However, Tetranychus species infested the plantings done during the dry and hot
seasons. Four major insect species caused major damage on the vegetable leaves, stems and
fruits with the most important species being aphids, cutworms, flea beetles and red spider mites.
Some nine insect species were of minor importance, as their infestation had less damage and
hence little impact on yield losses. Three other beneficial species were identified as natural
enemies of the insect pests. It is recommended that these be considered for conservation in pest
management strategies designed for the management of the pests.
Key words: AILVs, Insect pests, crop damage, Tetranychus, Natural enemies.
C2084. DISTRIBUTION OF Potato Tuber Moth (Phthorimaea operculella Zeller) AND
DAMAGE CAUSED ON POTATO TUBERS (Solanom tuberosum L) IN FARMERS
STORES
Olubayo, F., Were, S., Nderitu, J., Kilalo, D. and Koech, A.
University of Nairobi, Department of Plant Science and Crop Protection. P.O Box 29053-00625
NAIROBI
Abstract
Potato tuber moth complex of P. operculella (Zeller), Tecia solanivora (Povolny) and
Symmetrischema tangolias (Geyen) has a worldwide distribution and is a major pest of potatoes
affecting seed potato and ware potato in the field and store. A survey was undertaken in five
major potato growing regions of Kenya to identify the pest species and determine the distribution
of the pest and damage on tubers. Five thousand tubers were collected randomly from four
quarters of farmers’ stores from different areas and transported to the entomology laboratory at
Kabete Campus University of Nairobi for storage. Destructive sampling was done on the tubers
aGRO 2011 Biennial Conference to determine the damage and moths’ activity on collection and after three months of storage.
Adult moths emerging after three months of storage were trapped and the species occurring in
different regions identified using entomological identification keys for Lepidoterans. Mines and
larvae in tubers were counted to assess damage. Damage on tubers at collection and after three
months of storage was not significantly different between the five main areas where they were
collected (p<0.05). However, Njambini area had the least number of larvae and mines at initial
assessment while Bomet and Limuru had highest number of larvae and mines, respectively. After
three months of storage, Limuru had the highest number of larvae and mines in tubers while
Njambini and Meru had the least number of mines and larvae. Only one pest species
Phthorimaea operculella was identified. These results indicate continued activity of moths in the
stores and that there are areas such as Njambini where PTM infestation and activity is minimal.
The area could be considered for seed production complemented by some management of the
pest in the store for preservation.
Key words: Solanum tuberosum, Phthorimaea operculella, PTM Larvae,
C2088. YIELD PERFORMANCE OF POTATO CLONES WITH DURABLE
RESISTANCE TO LATE BLIGHT
Onditi J. O1., S.W. K Nderitu1 and J.A. Landeo2
1
Kenya Agricultural Research Institute (KARI), Tigoni P. O. Box 338-00217 Limuru
2
International Potato Centre (CIP), Sub-Saharan Africa Office Nairobi. P.O. Box 25171,
Nairobi, Kenya
Abstract
Higher yielding potato varieties are highly demanded by farmers and consumers. This study was
conducted to determine yield performance of 15 potato clones derived from a breeding
population with durable resistance to late blight. Trials were carried out over two cropping
seasons at Tigoni, Molo, Nyandarua and Meru. Data was collected on plant vigor, number of
marketable size tubers and tuber yield. There was significant (P=0.05) variation in yield
aGRO 2011 Biennial Conference performance of different genotypes across the different sites. Four clones, CIP 393077.159,
393077.54, 393111.13 and 395112.36 were identified with significant (P=0.05) higher plant
vigour than the rest of the genotypes. Two of these, CIP 393077.159, 393077.54 were found with
significant (P=0.05) higher mean yield of 48.2 T/ha and 52.4 T/ha, respectively than that of the
highest yielding check variety Tigoni which yielded 36.7 T/ha. The two higher yielding clones
did not however, have significant higher number of tubers per plant than the rest of the clones
but had a good mixture of seed and ware tuber grades. Due to higher yields, the two clones
identified in this study were recommended for release ..
Key words: Potato, Solanum tuberosum, yield, vigour, tubers, varieties
C2091. SCREENING FOR DROUGHT RESISTANCE IN LARGE SEEDED COMMON
BEAN IN KENYA
Ombaka J. O., P. M. Kimani, R. D, Narla, M.W. Mburu and J.M. Wambugu
Department of Plant Science and Crop Protection, University of Nairobi, P.O Box 29053-00625
Nairobi, Kenya
Abstract
Common bean (Phaseolus vulgaris L.) is major grain legume improtant in human consumption.
Andean bean genotypes are prefered for grain type and colour and constitute 60% of common
bean production in eastern and central africa. Drought causes loss of 395,000t annually in
Africa. Genotypes resistant to drought do exist. The objective of this study was to select large
seeded bean genotypes resistant to drought, carry out participatory variety selection and
determine traits associated with drought resistance. Study materials of 175 genotypes of diverse
characteristics from CIAT core collections, regional and national breeding programs, gene bank,
and local released varieties were evaluated for five seasons in drought nursery at Kabete from
2008 to 2010 long rain season. They were evaluated in complete randomized block design under
irrigated (IR) for non stress and non-irrigated (NIR) for drought stress treatments replicated three
aGRO 2011 Biennial Conference times. The whole trial was irrigated up to flowering stage to establish stand uniformity. NIR trial
was later subjected to drought stress while IR trial received supplemental sprinkler irrigation as
required. A combined analysis for water treatment and season effects were subjected to analysis
of variance with 5% and 1% probability considered significant and highly significant
respectively. Severe drought was experienced in short rain 2008 with drought Intensity Index
(DII) 0.75. Seventeen genotypes were selected for higher grain yield from the three market
classes including CIM-RM-02-01-07 and CIM-RM-02-04-03, ECAB 0031 and CIM-RK-03-0314, NS 15457-3 and Sharp black. Drought severely reduced the grain yield by 22.3% in 2010 and
33% in 2009. Farmers selected 12 genotypes including NS 15454-28, MR14215-5-1P, CIM-RK03-03-01, GCI-Cal 271-AR2, AFRI 708 and KAB 150. Days to flowering (DF), days to maturity
(DM), 100 seed mass and pod harvest index (PHI) were positively correlated, but 100 seed mass
and pod harvest index were highly correlated to non-irrigated grain yield. We recommend use of
days to maturity, 100 seed mass and pod harvest index for selecting common bean genotypes
under drought stress.
Key words: Sugars, Red kidney, Red mottled. Participatory, Andean
C2092. SCREENING FOR DROUGHT RESISTANCE IN SMALL SEEDED COMMON
BEAN
Ombaka J. O., P. M. Kimani, R. D, Narla, M.W. Mburu and J.M. Wambugu
Department of Plant Science and Crop Protection, University of Nairobi, P.O Box 29053-00625
Nairobi, Kenya
Abstract
Common bean (Phaseolus vulgaris L.) is extremely sensitive to drought. About 396,000t grain is
lost annually in Africa. Drought resistant genotypes exist. This study was conducted to select
small seeded bean genotypes resistant to drought, carry out participatory variety selection and
determine traits associated to drought resistance. Study material of 160 genotypes of diverse
characteristics from CIAT core collections, regional and national research programs, gene bank,
released and local varieties were evaluated in drought nursery for five seasons 2008 to 2010 at
Kabete, University of Nairobi. Experiment was organized in complete randomized block design
(CRBD) evaluated under two treatments, irrigated (IR) for no stress and non-irrigated (NIR) for
drought stress replicated three times. Whole trial received sprinkler irrigation water up to
aGRO 2011 Biennial Conference flowering stage to establish stand uniformity. Irrigated trial received supplemental irrigation
water as required while NIR trial was subjected to natural rain. A combined analysis for water
treatment and season effects were subjected to analysis of variance with 5% and 1% probability
considered significant and highly significant respectively. Severe Drought Intensity Index (DII)
0.72 in short rain 2009 reduced grain yield by 60%. Moderate DII 0.45 in 2010 reduced grain
yield by 40%. Twenty genotypes performed better than check variety by 55% and included GCIZEBRA-268-RAR-1, CIM-NAV02-02-11-1, MR 13508-7, RWR 2178. Farmers selected 12
genotype including GCI-CAL 271-AR2, AFRI 708 and KAB 150. Days to flowering (DF), days
to maturity (DM), 100 seed mass and pod harvest index (PHI showed positive correlation under
drought evaluation in all grain type categories. The traits 100 seed mass and pod harvest index
were highly correlated to non-irrigated grain yield. We recommend use of 100 seed mass and
pod harvest index for selection of common bean genotypes under drought.
Key words: Cariocas, Pintos, Purples, Small reds, Navy, Mesoamerica
C2095. SCREENING OF MAIZE SINGLE CROSS HYBRIDS FOR TOLERANCE TO
LOW PHOSPHORUS
Ouma Evans 1, Thomas Matonyei1, Beatrice Were1, Joyce Agalo1, Dickson Ligeyo2,
Samuel Gudu1,
1
Moi University P.O.Box 1125, Eldoret, Kenya,
2
Kenya Agricultural Research Institute (KARI) Kitale, Kenya.
Abstract
Maize (Zea mays L.) is one of the world’s most important staple food crops; however, its
productivity is limited by phosphorus (P) deficiency in acid soils. The objective of this study was
to develop single cross hybrids from P-efficient inbred lines and screen them for tolerance to P
efficiency in the acid soils at Sega and Bumala in Western Kenya known to be low in available
P. Forty nine single cross hybrids were developed from high P parental lines and screened for
tolerance to low P (2-2.2mgP/Kg soil) in the field. The effect of P application (26kgP/ha) on
maize grain yield, ear and plant height was assessed. Mean grain yield for the hybrids was 42.3%
higher with P fertilizer than without P for the same hybrids. Plant and ear heights were reduced
aGRO 2011 Biennial Conference by about 14.8%. Thirty three per cent of these crosses were inefficient but responsive to P
application, 27% were efficient and none responsive and only 2% were efficient and responsive.
Grain yield was positively correlated (r = 0.57**) with plant height and ear height (r =0.60**)
and plant height with ear height (r =0.86***). However, grain yield had low and negative
correlation with days to 50% silking (r =-0.32) and days to 50% tasseling (r = -0.32). This study
has developed and identified P-efficient single cross hybrids that can be used either directly or in
developing 3-way and/or 4-way cross hybrids for use in acid soils of Western Kenya and in other
acid soil within the region.
Keywords: phosphorus, interaction, genotype, efficiency, responsiveness, genotype, acid soils.
C2125. VARIATION IN SUSCEPTIBILITY OF WHEAT PARTS TO MAJOR Fusarium
HEAD BLIGHT PATHOGENS
Wagacha J. M. a, b, U. Steinera, H.-W. Dehnea, J. W. Muthomic, E.-C. Oerkea
a
Institute of Crop Science and Resource Conservation, Division Phytomedicine, University of
Bonn, Nussallee 9, 53115 Bonn, Germany.
b
School of Biological Sciences, University of Nairobi, P. O. Box 30197-00100 Nairobi, Kenya.
c
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 3019700100 Nairobi, Kenya.
Abstract
Fusarium head blight (FHB) of wheat is caused by a complex of pathogens with F.
graminearum, F. culmorum, F. poae, F. avenaceum and F. tricinctum being the most common
worldwide. Besides ears, the species have been isolated from wheat roots, foot, stems, ears and
leaves. Greenhouse studies were carried out to investigate differences in susceptibility of wheat
parts – leaves, stems, kernels and spikelets – to the five Fusarium species inoculated at midanthesis. Tissue susceptibility was assessed by establishing Fusarium spp. re-isolation frequency
20 days post inoculation. Additionally, FHB severity and effect of the disease on grain weight
were assessed. Tissue susceptibility to the Fusarium isolates varied significantly (p ≤ 0.05) and
aGRO 2011 Biennial Conference was in decreasing order: spikelets (mean 83%), kernels (mean 79%), stems (mean 75%), and
leaves (mean 31%). Fusarium graminearum and F. culmorum were re-isolated in the highest
frequency from spikelets and kernels, respectively while the corresponding lowest re-isolation
frequencies were F. avenaceum and F. poae; and F. poae. Fusarium head blight was initiated
earlier and progressed significantly faster (p ≤ 0.05) on plants inoculated with F. culmorum and
F. graminearum than the other three isolates. Area under disease progress curve varied
significantly (p ≤ 0.05) and decreased in the order: F. graminearum, F. culmorum, F. tricinctum,
F. avenaceum and F. poae, respectively. All Fusarium isolates except F. poae caused a
significant reduction in 1000-kernel weight with F. culmorum resulting in the highest (87%)
reduction, compared to non-inoculated controls. Fusarium species infect vegetative wheat parts
where they may survive between cropping cycles and contribute inoculum for FHB development
in a subsequent crop.
Key words: Ears, Fusarium spp., leaves, stems, susceptibility, wheat
C2103. IDENTIFICATION OF A REFERENCE CROP TO ESTIMATE NITROGEN
FIXED BIOLOGICALLY BY PIGEONPEAS
1*
1
Wanderi. S.W., 2M.W.K. Mburu and 3I.G. Nkonge
Kenya Agricultural Research Institute, P.O. Box 27, Embu. 2Department of Plant Science and
Crop Protection, University of Nairobi P.O. Box 29053, Nairobi. 3Ministry of Agriculture, P.O.
Box 30040, Nairobi.
Abstract
Knowledge of quantifying N fixation by pigeonpeas is useful in assessing its nitrogen
contribution to sustainable crop production. An experiment was conducted in the greenhouse at
Kabete, University of Nairobi to identify the most suitable reference crop that could be used to
quantify N fixed by medium duration (ICEAP-00557) and long duration pigeonpeas (ICEAP00040 and ICEAP-00053). Maize (Hybrid-511 and Katumani-composite), sorghum (MB30 and
IS25545) and cotton (HART-89M and UKA-59/146) were evaluated as reference crops using
completely randomized design replicated three times. Plant dry mass (roots and shoots) and root
length density were determined at 120 days after planting for two seasons. The proportion of
nitrogen fixed by pigeonpeas was calculated using N-difference method. The results showed that
over 50% of the root biomass of all the crops was at the top 30 cm and it was more vigorous in
cereals than in pigeonpea. Cereals also showed higher root length density and accumulated more
shoot dry mass than pigeonpeas and if used as the reference crops they would underestimate N
aGRO 2011 Biennial Conference fixed as a result of temporal and spatial variation in N uptake from the soil. Cotton had similar
rooting characteristics and growth pattern as pigeonpea an indication of its suitability as a
reference crop. The amount of N fixed was significantly different among pigeonpea duration
types, and the values depended on the cotton variety used as a reference crop. Long duration
pigeonpeas fixed more N than the medium duration, when both cotton varieties were used as the
reference crops, suggesting any of the two varieties could be used to assess N fixed by the long
duration pigeonpeas. However, the medium duration showed negative values when cotton was
used as a reference crop in the first season. This implies a cotton variety or an alternative crop
that closely matches the growth pattern of the medium duration pigeonpea is needed.
Key words: Nitrogen difference method, reference crop and pigeonpea N fixation
A2099. EVALUATION OF SMALLHOLDER POULTRY PRODUCTION AND ITS
CONTRIBUTION TO HOUSEHOLD INCOME AND NUTRITION IN KIAMBU WEST
DISTRICT, KENYA
Wahome M.G1, P N Mbugua2 and L W Kabuage2
1
Ministry of Livestock Development, P.O. Box 47010-00100, Nairobi-Kenya
University of Nairobi, Department of Animal Production, P.O. Box 29053-00625, NairobiKenya
2
Abstract
Evaluating the contribution of poultry farming in Kenya is essential in the implementation of
poultry production policies amid a growing trend of agricultural intensification and urbanization.
Purposive and stratified sampling methods across two divisions with extreme agricultural
productivity in Kiambu West District, Central Kenya were used to evaluate the contribution of
poultry to household income, food supply, livestock and crop enterprises. Kiambu West District
borders Nairobi Metropolitan area, an important egg and poultry market. Limuru and Ndeiya
divisions were chosen for the study. A questionnaire was administered to eighty four households.
The households were stratified into three categories; less than 500 commercial chickens, more
than 500 commercial chickens and indigenous chickens and comparisons made between farmers
in the three categories. Focus group discussions and in-depth interviews with key informants
were used in addition to the questionnaire. The landless monogastric systems and the semiintensive systems were identified. Flock sizes per household ranged from 4 to 30 birds for
indigenous chickens and 200 to 2,300 chickens for commercial layers. Most of the farmers
aGRO 2011 Biennial Conference keeping poultry (59.3%) were 50 years and above. The contribution of poultry to household
income, dairy production and household nutrition was significant (P<0.05). Poultry contributed
significantly to household nutrition by directly providing animal protein and also improving the
purchasing power of the households. Poultry manure was used as a supplement in dairy cattle
production and complemented crop production. The net effect of keeping poultry was improving
the welfare of the households through increased income and better nutrition. Appropriate policies
addressing the improvement of the quality and cost of poultry feeds, marketing and delivery of
extension services can contribute to the development of the poultry industry and help alleviate
poverty.
Key words: Smallholder poultry farmers, Kiambu West District, Farm incomes, Nutrition
A2127. ASSESSMENT OF THE EFFECT OF FEEDING PROSOPIS POD FLOUR
BASED RATIONS TO LAYER CHICKENS ON LAYING AND EGG QUALITY
1
Wahome, R.G., Onyore, E., Murage, L., Choge, S., Kyuma, R., and Tendwa, J.
Department of Animal Production, University of Nairobi. P.O Box 29053-00625 NAIROBI
Abstract
To assess utilization of prosopis based diets in layer chickens, four iso-caloric iso-nitrogenous
layer rations were formulated in accordance with KEBS standards, and fed to groups of six
layers replicated three times. The treatment diets contained 0% prosopis, 10% prosopis, 20%
prosopis and 30% prosopis. The layer chickens were fed over a period of 5weeks. During this
time, egg production, external and internal egg quality was monitored. By the end of the
experiment the birds fed on 0%, 10% and 20% Prosopis diet had similar egg productivity and
egg quality. The birds on the 30% Prosopis diet, had a significantly lower (P<0.05) egg
production. An important observation is that the birds’ egg production improved greatly in the
subsequent week for all the diets except 30% Prosopis diet. Yolk weight was almost constant
across diets and there was no correlation between egg weight and the type of diet. There was no
significant diet effect on both the shell weight and albumen height. However, it was observed
that shell quality improved with higher levels of prosopis. Eggs produced from birds fed on 0%,
10%, 20% and the 30% Prosopis diets scored low on the colour chart. Addition of 10%, 20%
and 30% Prosopis to the diets diet added colour to the yolk showing that Prosopis has properties
that can be exploited to reduce the use of xanthophylls. It was concluded that inclusion of up to
aGRO 2011 Biennial Conference 20% prosopis pod flour in layer chickens rations did not only not affect appetite, egg production,
egg quality and feed efficiency but also had the potential to reduce xanthophylls use in achieving
the deep yolk color usually desired by many consumers of eggs.
Key Words: Prosopis juliflora pods, egg quality, laying rations,
A2120. APPLICATION OF ENZYME TECHNOLOGY TO IMPROVE THE
NUTRITIVE VALUE OF HIGH-FIBRE FEEDSTUFFS FOR NON-RUMINANTS
Waititu S.M. 1, C. M. Nyachoti2, B. A. Slominski2, J.G. Maina3 and J.O. Ochanda1
1
Center for Biotechnology and Bioinformatics, University of Nairobi, P.O. Box 30197 - 00100
Nairobi, Kenya; 2Department of Animal Science, University of Manitoba, Winnipeg, Manitoba,
Canada R3T 2N2; 3Department of Animal Production, University of Nairobi, P.O. Box 29053 00625 Nairobi, Kenya.
Abstract
A study was done to determine effects of supplementing a high (HF) and low (LF) fibre basal
diets with multicarbohydrases that degrade non-starch polysaccharides (NSP) on growth
performance and nutrient utilization in broiler chickens. The basal diets were formulated with or
without three blends of commercial enzymes (A, B or C) giving 8 treatments. The LF diet
(having 10.5% NSP) was based on wheat, corn, soybean meal, DDGS and canola meal, while the
HF diet (having 13.3% NSP) was based on sorghum, cottonseed meal, sunflower seed meal and
brewers’ dried grains. The constituent enzymes activities of each blend varied between 1,100 to
5,000 units (U) of cellulase, 100 to 1,000 U of pectinase, 50 to 400 U of mannanase, 40 to 1,400
U of galactanase, 850 to 1,500 U of xylanase, 250 to 1,500 U of glucanase, 2,000 to 10,000 U of
amylase, and 150 to 1,000 U of protease per kilogram of diet but were similar for invertase (600
U) and phytase (500 U). The diets were fed in mash form to male broiler chicks housed in
individual cages from 1 to 21 days of age. Birds fed HF diets had significantly lower feed intake
(FI), body weight gain (BWG), and higher gizzard-to-body-weight ratios than those fed LF diets.
Enzymes caused significant differences in BWG, metabolizable energy content of diets, apparent
ileal digestibilities (AID) of neutral detergent fibre, apparent total tract digestibilities (ATTD) of
phosphorus and calcium, degradation of NSP in digesta, and digesta viscosity. Enzymes
improved the FI, feed conversion ratio, and AID of crude protein and amino acids in birds fed LF
and HF diets but the effects were not significant. Enzyme blend having highest activities of
multicarbohydrases showed better effects on the measured response criteria. This study showed
aGRO 2011 Biennial Conference that addition of multicarbohydrases to LF and HF diets improved growth performance and
nutrient utilization in birds.
Key words: non-starch polysaccharides, multicarbohydrases, broilers, nutrient utilization,
growth performance)
aGRO 2011 Biennial Conference F2106. DEVELOPMENT OF A FLAT-PLATE SOLAR MILK PASTEURISER FOR
ARID PASTORAL AREAS OF KENYA
Wayua, F. O. 1*, Okoth, M. W2. and Wangoh, J.2
1
Kenya Agricultural Research Institute, National Arid Lands Research Centre, P.O. Box 147
(60500), Marsabit.
2
University of Nairobi, Department of Food Science, Nutrition and Technology, P.O. Box 29053
(00625), Nairobi.
Abstract
Milk marketing is an important income earning opportunity for people in arid pastoral areas of
Kenya. To minimise losses along the milk chain, traders boil milk using scanty wood fuel which
negatively affects the environment. The abundant solar radiation in these areas could be explored
for its suitability for milk processing. Therefore, a solar milk pasteuriser consisting of flat-plate
water heating collector and a 1.5 mm thick stainless steel cylindrical milk vat was designed and
tested in an arid pastoral area of Kenya. The milk vat had a capacity of 80 litres and a 50 mm
wide hot water jacket insulated with 38 mm thick fibreglass. Hot water produced by the collector
was used for pasteurising milk. Parameters measured included the maximum achievable water
temperature, maximum amount of milk to be pasteurised, temperature of milk, temperature of
hot water, total bacterial count and coliform in the pasteurised milk, solar radiation, ambient
temperature and wind speed. Maximum milk temperature inversely varied with the amount of
milk, reaching 81.4°C with 20 litres and 41.7°C with 70 litres. The optimum quantity of milk
that could be pasteurised by this device was 40 litres, heated to 69.7°C in an average of 1.3±0.1
hours, at an average insolation and ambient temperature of 22.5±0.9 MJ.m–2.day–1 and
29.8±0.1°C, respectively. The average temperature difference between hot water and milk being
pasteurised was 8.1±0.6°C. Total bacterial counts in pasteurised milk were less than 10 cfu.ml–1
while coliform counts were negative. The system had a payback period of 4.3 years. This lowcost solar milk pasteuriser is appropriate for arid pastoral areas without grid electricity, where
milk marketing is an important income source, and where most of the milk is boiled using
firewood.
Key words: Flat-plate solar milk pasteuriser, design, performance
87 aGRO 2011 Biennial Conference C2108. TOLERANCE OF MAIZE VARIETIES TO INFECTION BY ASPERGILLUS
FLAVUS AND AFLATOXIN ACCUMULATION
*Weru R. W., J. W. Muthomi, G. N. Chemining’wa and E. W. Mutitu
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 3019700100, Nairobi
Abstract
Recurrent outbreaks of aflatoxin poisoning in Kenya pose a major food safety concern
considering that maize is the main staple food in the country. A study was conducted in Mwea
and Waruhiu over two growing seasons to evaluate the susceptibility of 16 maize varieties to
Aspergillus flavus and aflatoxin accumulation. The varieties tested were H513, Duma 43,
DK8031, DH01, DH02, DH04, Panner 77, Panner 7–19M, Panner 4M, Panner 67/5243, H515,
H516, KCB, H614, Pioneer 3253 and Katumani composite. Cobs were inoculated with A. flavus
in the field by silk channel inoculation method. Aspergillus rot assessment was done at
physiological maturity. At maturity cobs were harvested, dried to 13% moisture content. Subsamples (500 g) were adjusted to 10, 13.5, 15, 17 and 20%. Percent kernels infection with
Aspergillus flavus was determined by plating kernels on agar medium while aflatoxin content
was determined by enzyme linked immunosorbent assay (ELISA). The varieties differed in
visual Aspergillus rot rating with varieties Katumani and Katumani composite B having the
lowest rating while H614 had the highest Aspergillus infection. Husk coverage also influenced
the aflatoxin contamination with variety P77M, which had a loose coverage having a higher
aflatoxin concentration. Aspergillus flavus kernel infection was significantly affected by
sampling time, moisture content and variety. Samples stored at 17% moisture content had
significantly higher A. flavus kernel infection. Most varieties were susceptible to Aspergillus
flavus infection and had aflatoxin levels greater than 10µg kg-1 aflatoxin B1 allowed in Kenya.
The study demonstrated the need for development of varieties that are resistant to Aspergillus ear
rot as an option for managing aflatoxin poisoning.
Keywords: Aflatoxins, Aspergillus flavus, ear rot, maize, mycotoxins, resistance.
88 aGRO 2011 Biennial Conference F2013. THE POTENTIAL OF CASSAVA VALUE CHAIN IN ENHANCING FOOD
SECURITY AND INCOME GENERATION BY SMALL HOLDER FARMERS IN
KENYA
Jasper K. Imungi
Department of Food Science, Nutrition and Technology, Faculty of Agriculture, University of
Nairobi
Abstract
Africa is the biggest user and producer of cassava (Manihot Esculenta), the World’s fourth
ranking energy crop and staple food for around one billion people in 105 different countries of
the World. However, despite increasing demand and production potential, cassava still remains
an ‘orphan crop’ in many countries of Africa, usually cultivated only by small subsistence
farmers with little or no access to improved varieties or inputs, cut off from commercial scale
marketing or agro-processing industries. This is the same case in Kenya, where cassava has ever
been treated as a famine crop, to fall back on when popular staples are inadequately available. A
lot of research has been carried out to develop high yielding, non disease prone varieties, but the
attitude has still not changed to mainstream cassava into diets, and commercial production,
marketing and agro-processing in the country. This paper explores the use of value chain
approach to bring out its potential to enhance food security and the livelihoods of communities
through increased production, marketing and value addition, and incorporation into local
dietaries.
89 aGRO 2011 Biennial Conference C2129. EFFICACY OF NICOSULFURON IN THE CONTROL OF WEEDS IN MAIZE
Ariga1, E.S.; R. Narla1, P. Amuyunzu2, Kirimi 2, R. Nyankanga1 and R.W Michieka1
1
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 2905300625, Nairobi, Kenya
2
Twiga Chemicals Industries Ltd., Division of Agriculture, P.O. Box 30172-0010, Nairobi,
Kenya.
Abstract
Maize is the main staple food for majority of Kenyans. Weeds are the major constraint in maize
production. In search of an effective weed control method, a trial was carried out at the
University of Nairobi farm, Kabete, to determine efficacy of Nicosulfuron in weed control in
maize. Old and new stock of nicosulfuron at 100 and 125 g/ha with or without a surfactant
(Agral 90 at 0.2% v/v) was used. These treatments were compared with post directed paraquat at
0.5kg/ha (farmer’s practice) and weed free and no weeding controls. Results revealed that both
old and new stock of nicosulfuron at 100 kgha-1, applied without surfactant, were equally
effective in controlling weeds across weed species. The most difficult weeds to control in both
cases were Cyperus rotundus and esculentus. The herbicide prevented weed regeneration as
shown by low weed count, by species, three and a half months after application. Paraquat
controlled Amaranthus hybridus and Galinsoga parviflora. The rest of the weeds were scorched
up to four weeks after application then the weeds recovered and population increased till
senescence. Old stock of nicosulfuron was slightly more toxic than new stock at the same rate in
both seasons. Increasing the rate of nicosulfuron from 100 g with Agral to 125g/ha with Agral
significantly increased its toxicity to maize in season two (p< 0.05) but not in season one.
Treatments did not have significant effect on grain yield. Yield ranged from 3.0 to 4.6 t/ha in
season 1 and 2.5 to 4.4 t/ha in season 2. The presence of weeds in maize throughout the second
season reduced maize yield by 36 percent compared to weed free throughout the season.
Nicosulfuron is effective in controlling broadleaf, grasses and sedges in maize at the
recommended rate of 100g/ha with Agral 90 0.2% v/v.
Key words: Efficacy, nicosulfuron, weed control, phytotoxicity, maize
90 aGRO 2011 Biennial Conference SUBTHEME 3
AGRIBUSINESS, EXTENSION AND TECHNOLOGY TRANSFER
91 aGRO 2011 Biennial Conference A PARADIGM SHIFT IN CURRICULA DEVELOPMENT PROCESSES IN PUBLIC
UNIVERSITIES: Towards a responsive and participatory multi-stakeholder approach
Ambuko, J1., Maina, J.G2, Chemining’wa G.N1. and Lopokoiyit M3.
1
University of Nairobi, Department of Plant Science and Crop Protection. 2University of
Nairobi, Department of Animal Production. 3Egerton University, Department of Agricultural
Education and Extension
Abstract (E3001)
The mandate of public universities is teaching, research and outreach. To fulfil this mandate, it is
incumbent upon the universities to develop and deliver curricula that are current, relevant and
responsive to the needs of society. However curriculum development and review processes in
most public universities are lengthy, non-inclusive and academia driven. This situation does not
lend itself to the dynamic agricultural industry where consumer, farmer and technical knowledge
and skills are in constant flux. Increasing external and internal pressures calls for a paradigm
shift in curriculum development and delivery processes, towards a responsive and participatory
multi-stakeholder approach. This study was done to critically review curriculum development
and review process and establish the effectiveness of stakeholder engagement in Egerton and
Nairobi Universities. Objectives of the study were to document the main stages of the curriculum
development in selected public universities, the time taken to develop and review curricula,
assess stakeholder selection and engagement in curriculum development and delivery processes.
Data was collected using a semi structured questionnaire, desktop review of past reports and and
key informant interviews. The questionnaire was administered to five lecturers randomly
selected from five departments at the University of Nairobi’s college of Agriculture and
Veterinary Sciences and two departments at Egerton University. The findings show that
development of new curricula takes a minimum of two years in both universities while the
review process takes longer. Most respondents observed that the many stages in curriculum
development prolonged the process yet they did not add much value. The study also revealed that
there is minimal stakeholder engagement in curriculum development and delivery processes and
that the selection process is subjective. From the synthesis of information gathered in the study,
the paper proposes a paradigm shift in curriculum development and delivery processes at the
macro, meso and micro levels to ensure meaningful stakeholder engagement and ensure
responsiveness of curricula to internal and external changes. The paper also proposes some
strategies that universities can use to reposition themselves as network brokers in the agricultural
information and innovation systems.
Key words: Curriculum development, stakeholders, higher learning, agriculture
92 aGRO 2011 Biennial Conference E3003.MAINSTREAMING AND REVITALIZING WOMEN GROUPS IN
AGRIBUSINESS IN RURAL KENYA THROUGH MICROFINANCE
Bwire John Peter
Kenyatta University, P.O Box 43844-00100, NAIROBI, KENYA
Abstract
This paper sets out to investigate the role and effects of women groups in small scale agriculture
and business in Kenya. In terms of gender, this paper assumes that women are the majority
involved in rural market economy at every shopping center in Kenya, yet the government and
private sector have done very little to factor in mechanisms that can empower and rejuvenate
their struggles. Some of the women in the rural are widows, separated or sole bread earners
whereas their means of economic base are low.The objective of the study is to empower rural
women financially by sensitizing them to access microfinance services. This will enable them
not only to expand their economic base in business and improve agricultural productivity but to
break shackles of poverty and gender based cultural barriers that demean women, perspectives
that have not been factored in enough. The study is motivated and justified by the fact that little
focus has been accorded to rural poor women whose efforts if tapped and synergized would help
mitigate poverty and generate knowledge that other stakeholders, planners and government
policy makers can refer to. In this way, women will help mitigate poverty and ensure sustainable,
accountability values both in production, marketing and community social welfare. Data
collection will involve both primary and secondary sources. Purposive and stratified random
sampling techniques will be used. Questionnaires, Focus Group discussions (FDG), in depth
interviews and participant observation will be used for data collection. The respondents will be
sampled from business and working women, men and youth. Qualitative method of data analysis
will be used and synthesized thematically according to the study objectives. The use of
Quantitative analysis will be mainly for illustrative purposes.
Key Words: Gender mainstreaming, SME, Sustainability, Microfinance, poverty mitigation.
93 aGRO 2011 Biennial Conference E3004. STATUS, CONSTRAINTS AND MARKETING OPPORTUNITIES FOR
CANNING NAVY BEAN IN KENYA
Chemining’wa, G. N., O.M. Kitonyo and J.H. Nderitu
00625, Nairobi
Abstract
Navy (small white) bean is one of the most important grain type predominantly grown by the
smallholder farmers in eastern Africa. It is a pro-poor commodity that not only supports food
security, but also offers new options for smallholder farmers to enter higher value markets in
Europe and North America. However, the navy bean subsector in Kenya has not been
characterized. A study was conducted to determine the status, challenges and marketing
opportunities for canning navy bean in Kenya. Primary data were obtained by interviewing navy
bean producers, processors, resource experts, regulators and consumers using semi-structured
questionnaires. Secondary data were collected from published work and available statistics. The
survey showed that production of navy beans is very low and is mainly centered in Rongai and
Nakuru districts of Nakuru County. The average farm size under navy beans is 0.2 acres.
Production drastically declined in the 1990s due to the collapse of contractual arrangements
between producers and processors. Processors procured navy beans from large-scale traders who
sourced them through Moyale. Njoro canners, Kabazi canners and Premier foods were the main
navy bean processors during the survey period. Farmers in the study area rarely used fertilizers to
produce navy bean. The main challenges included low producer prices, lack of good quality
seed, poor agronomic and post harvest mangement, and lack of market information. The major
export markets for navy bean are in Europe and United States of America. The major suppliers
of navy bean to Kenya are China, Argentina and Ethiopia where an industrial company ACOS
has significant investment. The demand for canned navy bean among the middle class in Kenyan
cities is growing. There is need for high quality seed, improved agronomic management,
stakeholder linkages along the value chain and establishment of incentives to spur the navy bean
subsector.
Key words: Navy bean, Nakuru, production, constraints, Kenya
94 aGRO 2011 Biennial Conference E3006. URBAN FOOD PRODUCTION EXTENSION AND INSTITUTIONAL
DEVELOPMENT
1
Diana Lee-Smith, 1Ngugi Ndungu and 2John Mwangi
1
Mazingira Institute, Nairobi, Kenya
2
Nairobi and Environs Food Security, Agriculture and Livestock Forum (NEFSALF)
Corresponding authorl: [email protected]
Abstract
The paper is based on the findings of research carried out 2002-2008 and published in African
Urban Harvest, Prain et al. (eds) 2010 using sample surveys and in-depth qualitative research, as
well as statistics from Kenya’s 2009 census. Results show that almost 200,000 Nairobi
households engage in urban crop production and 69,000 households keep livestock – including
54,500 cattle and 81,500 sheep and goats. The Kenya government’s agriculture and livestock
extension apparatus engages with these systems in Nairobi, through the Nairobi and Environs
Food Security, Agriculture and Livestock Forum (NEFSALF), as a means of developing
appropriate institutions and policies. Nairobi became the pilot for Phase 2 of the National
Agriculture and Livestock Extension Program (NALEP) and a national Urban and Peri-urban
Agriculture and Livestock Policy (UPAL) is being drafted. While the proportion of Nairobi
urban farmers so far engaged with the civil society forum and the Government extension system
of training and visits that links to it are small (under 2 percent), the benefits to those farmers and
to the practice and status of urban farming are considerable. Challenges remaining are the
refinement of the draft UPAL policy, its wide acceptance and its entrenchment in new structures
of devolved local government – both county and urban. Only then can the knowledge gained
from years of research and practice be seen to influence policy and institutional reform
effectively.
Key words: Urban agriculture, urban livestock, extension, policy, institution-building.
95 aGRO 2011 Biennial Conference E3007. INCENTIVES AND CONSTRAINTS OF FINANCING MECHANISMS FOR
COMPLIANCE TO GLOBALGAP STANDARDS AMONG SMALLHOLDER
HORTICULTURAL FARMERS IN KENYA
Kangai Elosy1*, Mburu John 1, Nyikal Rose 1
1
Department of Agricultural Economics, University of Nairobi,
Abstract
This study draws on the case of smallholder fresh produce production and marketing in Eastern
and Central Kenya to analyze incentives and constraints of financing mechanisms for compliance
to GlobalGAP standards. GlobalGAP standards were enforced among smallholder farmers
without putting in place the corresponding financial arrangements. This study sought out to
understand the incentives and constraints hindering the accessibility to compliance to
GlobalGAP standards. The study relied on community-level surveys including Participatory
Rural Appraisal, Focus Group Discussions and Key Informant Interviews. Systematic and
purposive sampling procedures were used to select participants in the study. Findings indicate
that capital constraint is ranked among the first three most important factor hindering
GlobalGAP compliance. Farmers adopted four broad mechanisms to finance compliance. These
included individual financing; input credit from individually contracted farmers to ‘subcontracted’ farmers, group financing and infrastructure development alongside input credit by
exporters. Over fifty percent of non-contracted farmers in Buuri production area in Eastern
province, financed compliance through input credit from individually contracted farmers.
Individual financing was reported by less than ten percent of smallholder farmers in Buuri and
Kirinyaga production area of Central Province. Group financing mechanism was most common
in Kirinyaga and to a smaller extent Mbooni of Eastern Province. Each mechanism has varying
incentives and constraints, affecting the cost, period taken to comply and the prospects of
remaining compliant. Three policy implications emanate from this study. First, financing
smallholder horticulture for compliance to GlobalGAP should be more innovative and informed
by the compliance arrangement. Secondly, stronger linkages with financiers are encouraged to
devise products which meet the financial needs of smallholder farmers. Thirdly, the proposed
horticultural development fund should prioritize the needs of smallholder farmers to enable them
remain in business.
Key words: GlobalGAP compliance, Financing, Incentives, Constraints, Smallholder
Horticulture
96 aGRO 2011 Biennial Conference E3008. COMPARATIVE ANALYSIS OF ACCEPTABILITY OF CAMEL MILK
AMONG RURAL AND URBAN CONSUMERS IN KENYA
Emukule J. I1, Ngigi M1, Guliye A.Y2 and Lamuka P.O3
1
Egerton University, Department of Agricultural Economics, P. O. Box 236, Njoro;
2
Egerton University, Department of Animal Production, P. O. Box 236, Njoro;
3
University of Nairobi, Department of Food Science, Nutrition & Technology, P.O. Box 2905300625, Nairobi.
Abstract
The demand for information on consumer food consumption and satisfaction by the public and
private sector is increasing. The information on perceptions and attitudes of rural and urban
consumers’ on acceptability of camel milk is increasingly necessary for the popularization and
development of camel milk marketing strategies. This study investigated the consumer
perceptions and attitudes towards acceptability of camel milk in Isiolo and Nairobi counties. A
questionnaire was administered to both rural (Isiolo county) and urban Nairobi County)
consumers using multistage sampling approach and data analyzed using the Likert scale scoring
technique. The results show that 66% of the urban consumers were dissatisfied with the
packaging compared to 19.1% of the rural consumers. In case of pricing, 53.3% of the urban
consumers were dissatisfied camel milk price compared to 6.4% of the rural based consumers.
With respect to perceptions on the nutritive value of the milk, 73.1% and 91.5% of the
consumers in Nairobi and Isiolo County, respectively strongly agree that the camel milk is highly
nutritious. Eighty three percent (83%) and 94.9% of consumers in Isiolo and Nairobi County,
respectively, believed that camel milk has therapeutic properties. Both the urban and the rural
consumers believed that camel milk can be able to treat stomach upsets, blood pressure, diabetes
and stomach ulcers. In both areas over 97% of the consumers were highly satisfied with the taste
of the milk. The implications of these findings are that to enhance the consumption of camel
milk in urban areas, there is need to improve the packaging material and the pricing should be
adjusted to match with that of cow milk.
Keywords: Camel milk, consumer perceptions and attitudes, therapeutic
97 aGRO 2011 Biennial Conference E3009. RESOURCE USE EFFICIENCY OF SMALLHOLDER CROP PRODUCTION IN
THE CENTRAL HIGHLANDS OF ETHIOPIA
Mussa, Essa1*2, Gideon A. Obare1, Ayalneh Bogale2, Franklin P. Simtowe3
1
Egerton University, Department of Agricultural Economics and Business Management, Kenya,
African Centre for Food Security, University of Kwazulu Natal, Pietermaritzburg, South Africa
3
International Crops Research Institute for the Semi-arid Tropics (ICRISAT), GT - Institutions,
Markets,Policy & Impacts, Kenya
2
Abstract
Ethiopian highland agriculture is dominated by high dependency on rainfall, traditional
technology, high population pressure, and severe land degradation combined by low level of
productivity. These and other related situations have led to resource use efficiency and
agricultural productivity to be the major policy concerns in Ethiopia. In this article data from 700
households in the central highland districts were used to assess farm-level resource use
efficiency and to determine factors that influence inefficiencies in the production of teff
(Eragrostis tef), wheat and chickpea, the major important crops in the country. The study
established that smallholder crop farmers are resource use inefficient. Moreover, a two-limit
Tobit regression model results reveal that inefficiency in resource use is positively and
significantly affected by family size, farming experience and membership to associations. It is
also found that those households whose decision makers have roles in community activities show
improved resource use efficiency. Moreover, the findings also show that eliminating resource use
inefficiency could add about 31.28% to the minimum annual income required for an average
household sustenance. Findings of the study implies that resource use efficiency and productivity
gains are likely to be significantly improved through expansion of nonfarm sectors, reform of
farmer related associations and integrating community leadership in various social capital
enhancing programs. Moreover, market access and infrastructure development would likely
increase efficiency and productivity hence improves the livelihoods of rural households
Keywords: DEA; Tobit; Resource use efficiency; Productivity; Smallholder; Crops; Ethiopia
98 aGRO 2011 Biennial Conference E3010. GLOBALGAP COMPLIANCE ARRANGEMENTS AMONG
HORTICULTURAL PRODUCERS IN CENTRAL AND EASTERN KENYA: Dynamism
and driving factors
Gachigi John 1 and John Mburu2
2
Department of Development Studies, St. Paul’s University
Corresponding author: Email: [email protected]
Abstract
This study explores the changes that have taken place since the enforcement of GlobalGAP
standards among smallholder’s horticultural farmers in Central and Eastern Kenya in 2005.
Efforts to overcome the challenges of implementing GlobalGAP have been hampered by the
dynamism in compliance among stakeholders and within farmer groups. Little knowledge
exists on the effect of dynamisms on compliance and sustainability and hence the purpose of the
study. Understanding of the dynamism within smallholder horticulture in the face of
GlobalGAP offers lessons to stakeholders as they roll out the KenyaGAP. The study was
carried out in four districts in Eastern and Central provinces. The main objective was to
examine how different compliance mechanisms emerged initially and how they have been
changing over time. The study employed a descriptive research design along with qualitative
research methods for data collection. There were key informant interviews and focus group
discussions, observation and PRA tools. The findings show that the standards were introduced
around the same time in all areas by exporters and Ministry of Agriculture. After the initial
training, there have been limited follow-ups. The study also established that dynamism is
highest in levels of compliance, monitoring and evaluation, group participation and
contracting. The main causes for this dynamism are inadequate capital, limited knowledge,
cost-cutting measures, leniency, breached contracts and moral hazard. The study also
established main driving factor of change in compliance as spreading of risks, lack of
knowledge, moral hazard, laxity in enforcement of standards and weak linkages between
stakeholders. The findings of this study are important to stakeholders in devising
implementation strategies to achieve sustainability and boost compliance. Farmers need
more information regarding GlobalGAP to make informed decisions. The findings will also
inform policy makers and development partners on how to position new food safety
standards within the ever dynamic smallholder horticulture business.
Key words: GlobalGAP compliance, Dynamism, driving factors, smallholder horticulture.
99 aGRO 2011 Biennial Conference E3011. DETERMINANTS OF HOUSEHOLDS’ PARTICIPATION IN NGOSUPPORTED AGROFORESTRY ACTIVITIES IN KAKAMEGA FOREST, KENYA
JOSKY GWAKA1, JOB LAGAT1, JOHN MBURU2,
1 Egerton University, Department of Agricultural Economics and Agribusiness
2 University of Nairobi, Department of Agricultural Economics
Abstract
Kakamega Forest, the only remaining rainforest in Kenya and the furthest eastern remnant of the
Guinea-Congolean belt, has declined by 20% in the last 30 years due to population pressure and
encroachment. This has led to a shift of focus by households from getting goods and services
from the Kakamega Forest to participating in agroforestry activities around the forest. However
participation of households in the NGO-supported agroforestry programmes has not been
expanding as expected and the drivers of participation are not known. Against this background,
this paper aims at analyzing factors influencing households’ participation in NGO agro-forestry
activities that indirectly support conservation of Kakamega Forest. Multistage sampling was
applied in selecting a sample of 122 households that were interviewed in order to collect data for
this study. Heckman two-stage estimation procedure was employed, first to determine factors
that influence households’ probability of participation in NGO-supported agroforestry activities
and second to estimate factors influencing the extent of participation. The results indicate that
gender, education and off-farm income significantly and positively influenced participation of
households’ in NGO-supported agroforestry activities while age and distance to the market were
significant with negative effects. For the extent of households’ participation in NGO-supported
agroforestry activities gender and education were found to be significant with positive effects.
The study’s conclusion is that these factors form important drivers of households’ participation
in NGO-supported agroforestry activities and should therefore not be ignored by policy makers
and development practitioners. The study recommends that younger household heads and female
headed households should be targeted to boost participation. There should be investment in
education and creation of off-farm employment opportunities. Constraints hampering
development of markets should also be addressed if participation in NGO-supported agroforestry
activities is to be enhanced in the study area.
Key words: Agroforestry, Conservation, Heckman model, Kakamega Forest, Participation,
NGOs
100 aGRO 2011 Biennial Conference E3013. AN AUDIT OF KENYA’S LIVESTOCK EXPORT VALUE CHAIN
Irungu, P.1∗, P.M. Ithondeka2, E. Wafula3, S.N. Wekesa4, H. Wesonga3 and T.W. Manga2
1
Department of Agricultural Economics, University of Nairobi. P.O. Box 29053, Nairobi, Kenya
2
Department of Veterinary Services. Private Bag Kabete 00625 Kangemi, Kenya
Kenya Agricultural Research Institute (KARI). P.O. Box 32-00902 Kikuyu, Kenya
4
Kenya Veterinary Vaccines Production Institute (KEVEVAPI). P.O Box 18021 00500 Nairobi,
Kenya
3
Abstract
For a long time Kenya has demonstrated its desire to access lucrative export markets for its
livestock and livestock products. Although this desire matches the growing global demand for
livestock products and increasing interest in livestock and livestock products from Kenya by
livestock deficient countries, Kenya has not been able to meet the expressed demand. The
reasons for this failure have not been sufficiently documented. Even when the information is
available it is scattered in government and stakeholder documents and reports. Assembling such
information would avail the tools needed to design goal-oriented redressive packages to promote
trade. This study used the value chain approach to document the factors that limit livestock
export trade in Kenya. Questionnaire interviews were conducted with livestock producers
(pastoralists & ranchers), traders, processors and importers. Pastoralists cited livestock diseases,
poor roads and general insecurity as the main constraints to livestock supply. The ranchers
indicated that drought, livestock theft, diseases, and Kenya’s failure to meet sanitary
requirements as the main constraints. Livestock traders cited high cost and delays in obtaining
movement permits and disturbance by government officials along the stock routes. Processors
on the other hand mentioned Kenya’s failure to meet the international sanitary requirements.
The only importer interviewed indicated that trade restrictions, Kenya’s inability to control
livestock diseases and the distance between them and Kenya as the main constraints.
Stakeholders in the Kenya’s livestock export value chain should address these constraints to
revitalize export trade in livestock and livestock products.
Key words: Livestock export trade, value chain, Garissa, Laikipia, Kenya
101 aGRO 2011 Biennial Conference E3014. DETERMINANTS OF CATTLE MARKET PRICES IN MAASAILAND: A
GARCH-M APPLICATION
Irungu, P.1∗, B. Bett2, S.G. Mbogoh1, T. Randolph2, S.O. Nyamwaro3 and G. Murilla3
1
Department of Agricultural Economics, University of Nairobi, P.O. Box 29053, Nairobi, Kenya
2
International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya
3
Kenya Agricultural Research Institute, TRC, P.O. Box 362, Kikuyu, Kenya
Abstract
Livestock marketing provides an avenue to improving pastoral livelihoods and food security.
However, little is known regarding the factors that influence livestock market prices particularly
in Maasailand in Kenya. Knowledge of those factors could assist in designing market-based
incentives to promote cattle trade among the Maasai whose livelihood is solely dependent on
livestock. Cattle prices were collected in Oldonyonyokie, Olkiramatian, Shompole, and Ewaso
Ngiro livestock markets once weekly for 12 months between 2004 and 2005. The aim was to
assess the factors that influence cattle market prices in Maasailand. A generalized autoregressive
conditionally heteroscedastic-in-mean (GARCH-M) estimator was used because of
autocorrelation and heteroscedasticity problems inherent in such data sets. Four separate models
were fitted to the data, one for each market. The results indicate that animals with good to
excellent body condition fetched a premium price in all the four markets. Relative to crossbreeds, Maasai zebu fetched significantly lower prices in Ewaso Ngiro and Oldonyonyokie
markets. The period when school fees are due in May was associated with significantly higher
prices in all the four markets (p<0.05). The Easter holiday put upward pressure on cattle prices
in all the four markets. Trekked cattle sold at a discount relative to trucked ones. Rainfall was
significantly associated with higher cattle prices in Ewaso Ngiro market. The time trend had no
relationship with cattle market prices. In order to take advantage of high market prices, the
Maasai pastoralists should time their offtake to coincide with reopening of schools and public
holidays especially Easter. Supportive marketing infrastructure as well as introduction of cattle
auctions could go a long way to improving cattle marketing in Maasailand.
Keywords: Cattle market prices, Maasailand, GARCH-M, Kenya
.
102 aGRO 2011 Biennial Conference E3015. AN ASSESSMENT OF LIVESTOCK PRODUCTIVITY IN THE NILE BASIN
COUNTRIES: A MALMQUIST APPROACH
Irungu, P.1∗, L. Ndirangu2 and J.M. Omiti2
1
Department of Agricultural Economics, University of Nairobi, P.O. Box 29053, Nairobi, Kenya
2
Kenya Institute for Public Policy Research and Analysis, P.O. Box 56445, Nairobi, Kenya
Abstract
As the global demand for livestock products continues to rise, questions arise as to whether the
productivity of the existing stock will match the growing demand. Although the Nile basin
countries hold the single largest livestock population in the world, the productivity of these
livestock has not been documented. This study documented the state of livestock productivity in
five Nile basin countries (Ethiopia, Kenya, Sudan, Tanzania and Uganda) using a non-parametric
Malmquist approach. Secondary data were obtained from FAOSTAT spanning the 1985-2004
period. The focus was on cattle (beef and dairy) and poultry products (meat and eggs). The
results indicate that the productivity of beef and veal in the five Nile basin countries increased by
1.5% annually over the study period due to changes in innovation and technical efficiency. At
5.1%, Ethiopia had the highest productivity change for beef and veal most of which was due to
increased efficiency. A 3.3% increase in productivity of cow milk arose mainly from
technological change. Kenyan hens had the highest productivity in the region producing an
average of 4kg of eggs per hen annually followed by Tanzania (3.3kg/hen) and Ethiopia
(2.9kg/hen). Although the results indicate some real growth in particular sectors of the livestock
industry, the rate of growth is lower than that of the human population in the region. Therefore,
governments and other stakeholders in the livestock sector in the region should invest in
innovations and strategies that will improve livestock productivity to meet the growing demand.
Keywords: Livestock productivity, Malmquist index, Nile basin, TFP
103 aGRO 2011 Biennial Conference E3034. FACTORS AFFECTING ADOPTION OF NERICA RICE BY SMALLHOLDER
FARMERS IN MWEA, KENYA
Kabugua Lydia and John Mburu
Department of Agricultural Economics, University of Nairobi.P.O Box 29053-00625, NAIROBI
Abstract
In the past decade, a lot of emphasis has been placed on revitalizing agriculture as the engine for
economic growth in Kenya. Technological advancements such as introduction of NERICA rice
are necessary for agricultural development, but not a sufficient step towards increased food
production per se unless adopted. This study aims to fill the knowledge gap and to assess the link
between NERICA rice adoption by small scale farmers in Mwea, Kirinyaga County. The study
uses primary data which is subjected to a predictive design so as to give insight into the factors
influencing adoption of NERICA. A semi structured questionnaire was used to collect data and a
probit regression model used for analysis. Descriptive analysis shows that NERICA rice adopters
have more exposure to formal education than the non-adopters and rely more on family labor
than hired labor. Regression analysis shows that farmers’ decision to adopt NERICA rice is
positively influenced by total land owned, labor availability and input market. However adoption
is negatively influenced by distance to the nearest extension service provider. It therefore seems
that targeting farmers with access to more resources such as land and labor is likely to enhance
the adoption of NERICA rice in the study area. Further, increasing uptake of extension services
by bringing providers closer to farmers in Mwea is likely to boost adoption. Eventually these
policy measures are likely to contribute towards increased rice production by benefiting
agricultural stakeholders such as the producers and the government therefore enhancing food
security in the country.
Key words: adoption, NERICA rice, food security
104 aGRO 2011 Biennial Conference E3037. IMPACT OF MARKETING FACTORS ON PROFITABILITY OF
SMALLHOLDER DAIRY FARMERS IN NYERI COUNTY OF KENYA
Gichuki Anthony Kibuka
DEPARTMENT OF AGRIBUSINESS MANAGEMENT AND TRADE, KENYATTA UNIVERSITY
Abstract
The objective of the study was to identify marketing factors that contributes to low profitability
in small scale dairy farming enterprises in Nyeri County. Marketing chains were chosen as the
unit of analysis. The components of analysis included functional analysis to identify agents
involved in the chain and their roles, flow analysis to provide insights into the different subchannels and the flow of milk through the different channels, technical analysis to provide
information on constraints and technical gaps in the chain, micro analysis at operator level to
provide a detailed description of activities at each level in the chain and economic and social
impact analysis of the industry to the farmers. It was established that differences in relative
performance are due to differential marketing costs stemming from asymmetric access to
information, differences in choice of marketing channel and management of respective
marketing chains. In spite of marketing groups being owned by the same farmers, they have little
role in their management. The results do not support the hypothesis that vertical integration is a
effective way of operating dairy enterprises. In some cases the management deliberately delinks
from the other farmers and operates independently without reference to the members. This was
observed in two groups with one changing from a self help group to a limited company without
farmers’ knowledge. Although marketing groups are very important to farmers in the study area,
any integration either vertical or horizontal needs to be controlled and properly managed to
facilitate flow of information so that farmers can get maximum benefit.
Key words: dairy farming, Nyeri, marketing chains, integration
105 aGRO 2011 Biennial Conference E3017. IMPACT OF MOBILE PHONE-BASED MONEY TRANSFER SERVICES ON
SMALLHOLDER AGRICULTURE IN KENYA
Kirui∗ Oliver Kiptoo2, Julius J. Okello1 and Rose A. Nyikal1
2
1
International Maize and Wheat Improvement Centre (CIMMYT), P.O. Box 1041, Nairobi,
University of Nairobi, Department of Agricultural Economics. P.O. Box 29053-00625, Nairobi,
Abstract
The recent introduction of mobile phone-based money transfer services is seen to resolves one
idiosyncratic market failure farmers face, namely access to financial services. It facilitates
transfer of money to beneficiaries in a quick and cost effective way and offers an easy platform
for the small savings and transactions. This study employs propensity score matching technique
to examine the impact of mobile phone-based money transfer services on level of agricultural
commercialization, input use and farm incomes among rural farmers in Kenya. It uses crosssectional data collected from 379 randomly selected households in Central, Western and Nyanza
provinces in Kenya. One hundred and eighty eight of these households use mobile money
transfer (treatment group) while one hundred and ninety one do not use the services (control
group). Use of mobile phone-based money transfer services significantly increases level of
household agricultural commercialization by 37 percent, household per capita income by $224
and household per capita input use by $42. We discuss the implications of these findings for
policy and practice.
Key words: mobile phones, money transfer, impact, farmers, m-banking, Kenya
106 aGRO 2011 Biennial Conference E3020. DEVELOPING CORE COMPETENCIES OF AGRICULTURAL
PROFESSIONALS
Lopokoiyit, C. Mary, Christopher Onyango and Joash K. Kibett
Department of Agricultural Education and Extension, Egerton University. P.O. Box 536 - 20115
Abstract
Agriculture extension is a multidisciplinary discipline based on human interaction. It seeks to
improve the livelihoods of individuals and communities by providing a platform for information
sharing and learning among various stakeholders. Agricultural activities are diverse, holistic and
systemic hence the need to review the training of agricultural professionals to integrate
multidisciplinary competencies. The curricula of undergraduate programs focus on basic
sciences, extension and technical subject matter with little emphasis on professional skills that
enhance the personal effectiveness of the individual in managing the context of extension service
delivery. This study sought to determine the professional competencies required by extension
staff critical for the effective delivery of services through a training needs analysis of 417
extension agents from both the public and private sector. A Cross-Sectional survey design was
used and training needs were determined using the Critical Incident Technique (CIT) in which
respondents were asked to narrate effective and ineffective extension activities and attribute
behavioural and technical factors that lead to success or failure. The behaviours and technical
factors were categorised in themes and specific competencies from which training needs were
derived. Case studies of effective and ineffective extension activities are presented for
discussion. Respondents were also asked to suggest courses to be prioritised for training in the
undergraduate agricultural curricula. The training needs were grouped in five themes; Extension
education, Management, Agricultural economics, Agricultural engineering and Cross-cutting
issues. A critical basic need identified by extension agents is the need for training in computer
literacy and integration of ICT in the themes. The paper provides a premise to stimulate
discussions on core competencies required of agricultural graduates regardless of the area of
specialization.
Key words: Training needs, Critical Incident Technique, Core competency, Agricultural
Professionals
107 aGRO 2011 Biennial Conference E3022. INNOVATIVE TEACHING AND LEARNING APPROACHES THAT
PROMOTE THE DEVELOPMENT OF SUSTAINABLE AGRICULTURAL
Maina J. G. 1, J. Ambuko2 M.C. Lopokoiyit3 and G.N. Cheminingw’a2
1
University of Nairobi, Department of Animal Production. 2University of Nairobi, Department of
Crop and Plant Science. 3Egerton University, Department of Agricultural Education and
extension.
Abstract
Transforming agricultural education in Universities is critical to enable them to contribute to the
realization of Vision 2030 for the agriculture sector. Since the mid 1980’s faculties of agriculture
have experienced changes that include reduced government funding, reduced student enrolment,
increased competition for students, and changes in the role of government as the traditional
employer for Agricultural graduates. Universities must therefore respond to these changes by
designing relevant and responsive curricula using appropriate delivery methods responsive to the
changing demands of sustainable production systems and market driven economies. Graduates
require knowledge, skills, attitudes and professional competencies to enable them effectively
engage rural communities in developing innovative solutions to their complex problems. To
achieve these objectives there is need to develop student centred learning systems that reward
innovative and adaptable graduates. This demands a paradigm shift from dyadic transfer of
information to experiential and problem-based learning approaches. A study was done to
evaluate teaching-learning strategies used by lecturers in two universities, Nairobi and Egerton.
The objectives of the study were to assess the lecturer’s perceptions and understanding of
experiential learning and problem based learning. The study also sought to determine the
instructional methods used in he universities and evaluate adequacy of teaching – learning
resources. A cross sectional research design was used and data was collected using
questionnaires and document analysis. Majority of the lecturers had no formal training on
teaching methodologies and were not aware of the contents of the ISO 9001:2008 document on
teaching standards. The study showed that lectures were the main instruction method used, and
large classes and inappropriate classroom infrastructure made it difficult to use other
instructional methods. Further, the lecturers understanding of experiential learning was quite
diverse, in most cases showing a lack of understanding of the concept. There is need to retool
and equip staff with the appropriate skills and provide the necessary infrastructure and resources
to facilitate lecturers to adapt student centred teaching-learning approaches.
KEY WORDS: Experiential learning, Lecturers, Students, Teaching – learning strategies.
108 aGRO 2011 Biennial Conference E3023. AN ECONOMIC EVALUATION OF ALTERNATIVE LIVESTOCK DISEASES
CONTROL STRATEGIES: THE CASE OF THE CBPP QUARANTINE LINE IN
NORTH-EASTERN KENYA
1
Mbogoh Stephen G. and Joseph M. Gathuma2
1
Department of Agricultural Economics, University of Nairobi
2
Faculty of Veterinary Medicine, University of Nairobi
Abstract
Livestock keepers namely, pastoralists in the arid and semi-arid land areas (ASALs) of Kenya
face many marketing constraints. The imposition of livestock movement restrictions by the
veterinary authorities as a strategy for livestock diseases control is one of them. There a number
of life-threatening livestock diseases that are endemic in the ASALs of Kenya such as
Contagious Bovine Pleuro-Pneumonia (CBPP) that justify the case for livestock diseases control,
A CBPP Control Quarantine Line (CQL) that is intended to help prevent the spread of the CBPP
from the arid districts of north-eastern Kenya to the rest of the country has been in existence in
Kenya since the colonial (pre-1963) times. However, this CQL has been of great concern to the
pastoralists from the arid north-eastern Kenya because they view it as an impediment to their
main source of livelihoods. Available literature indicates that there is a dearth of information on
the economics of livestock diseases control and the impacts of this control on the welfare of the
pastoralists in the ASALs of Kenya. Therefore, this article attempts to narrow down that
information gap by examining the efficacy and economics of livestock diseases control in the
ASALs of Kenya, using the CQL as a case study. The study is based on the review of relevant
literature and interviews with key stakeholders in the livestock industry in Kenya. Data analysis
included modelling disease, risk and cost-benefit. A key finding of the study is that there is a
widely held view among the pastoralists and livestock traders that CBPP is not a serious problem
despite some officially recorded evidence that CBPP is a major threat to the cattle industry,
especially in the arid border districts of Kenya. To contain the CBPP menace in Kenya, the
government incurs a fairly high annual expenditure in excess of Kenya Shillings (KShs) 287.5
million on CBPP surveillance and control in the arid north-eastern districts of the country, in
addition to the costs of operating and maintaining the CQL. This study finds that Isiolo still
remains the main base for the CQL and that the majority of the cattle traded out of the Isiolo
District are sold under permissive conditions that allow cattle to cross the CQL without
observing the laid down CQL regulations. The CQL stipulations are further weakened by the fact
that there is no CBPP testing at all for the cattle destined either for slaughter in the Mombasa
109 aGRO 2011 Biennial Conference market or for fattening in the Coastal region ranches that are traded along the Mandera-WajirGarissa-Ijara-Tana River-Malindi stock route. Therefore, this study concludes that the current
CQL requirements in Kenya are characterized by operational difficulties and inefficiencies. It
would be more cost effective to shift the current CQL from Isiolo to the international borders of
the arid districts of north-eastern Kenya.
Key Words: Evaluation, Livestock Diseases Control, CBPP, Pastoralists, Marketing, Welfare,
Kenya
110 aGRO 2011 Biennial Conference E3024. DEVELOPMENT OF VALUE CHAIN FOR LINKAGE OF CASSAVA
PRODUCTION IN KALOLENI DISTRICT KENYA, TO MARKETS
Mbugua S Ka, Carine Dortub, Melanie Kostinekc, Charles M.A.P. Franzc, Willhelm
Holzapfelc, Moutairou Egounletyd, Philippe Thonartb, Moses Mengue.
a
University of Nairobi, Kenya; bUniversity of lieg, Belgium; cFederal Research Centre for
Nutrition and Food, Germany; dUniversity of Abomey-Calavi, Benin; fWorld Association of
Industrial Research Organization (WAITRO), Denmark.
Abstract
Kenya government has intensified efforts for improvement of cassava productivity, given the
ineffectiveness of maize in combating the worsening food insecurity in the country. Such efforts
can only succeed in an agribusiness system approach, incorporating value chains development to
link cassava farmers to markets. A case for value chain development based on cassava
processing to a gluten-free flour with doughing properties similar to those of wheat flour is
presented. Such flour can enable cassava farmers access market nationally for baking flour, used
for preparation of baked products such as Chapatti and Mandazi, at house hold or catering
business levels. The technology involved lactic fermentation, drying and partial gelatinization.
The technology was based on the already developed GARI production process (a cassava staple
in West Africa) but improvement were done in production process and nutritive value of the
end-products. These improvements were in the development of lactic acid bacteria culture (LAB
culture), incorporation of soybeans, coconut cream and carrots, and optimization of pressing
(dewatering) and drying systems. The cassava flour developed from this process was evaluated
for its performance in the preparation of acceptable house hold products from maize and wheat
flours. The LAB culture reduced fermentation time from more than 24 hrs by natural culture to
18 hrs, and generated stable and acceptable aroma in the end-products. The baked products
Chapatti and Mandazi prepared from 100% gluten-free cassava flour, were most acceptable and
indistinguishable from those made from wheat flour. The technology up-take and agribusiness
set-up was demonstrated and disseminated by establishing a cassava processing pilot plant for
Kaloleni women cassava smallholders, which is pictorially presented. The potential for the
developed cassava value chain in exploiting national market opportunities for baked products
normally produced from largely imported wheat and also in addressing food security and
poverty if replicated in areas unsuitable for maize production is discussed.
Key words: Cassava; Processing; Gluten-free Flour; End-products; Value-chain; Markets.
111 aGRO 2011 Biennial Conference E3025. ASSESSMENT OF FARMERS’ ACCESS TO FORMAL AND INFORMAL
MAIZE SEED INPUT CHAINS IN SEMI-ARID KENYA
Mburu, J1, Hellin, J.2 and Nyamai, D3
1
Deprtment of Agricultural Economics, University of Nairobi
2
International Maize and Wheat Improvement Center
3
Ministry of Agriculture
Abstract
Formal seed maize market chains have increasingly become important in supplying improved
seed maize to farmers and thus aiding in combating hunger and food insecurity. Smallholder
farmers in arid and semi-arid areas parts of Kenya can increase maize yields through the
widespread use of improved hybrid maize varieties. Farmer access to improved germplasm,
however, is limited. This is attributed to poor seed distribution and marketing in the rural areas.
To increase farmers’ access to improved seed, researchers and development practitioners first
need to understand how the seed maize market channels are structured, how they operate, the
bottlenecks to them operating more effectively and the reasons why farmers decide to access
seed via formal or informal channels. These issues are not clearly understood in the semi-arid
areas of Kenya. Against this background, this paper analyses the structure of maize seed input
chains in Machakos District and assesses factors that influence farmer participation in formal and
informal seed chains. Qualitative assessment on the structure of the seed input chains - based on
a market mapping approach - was followed by quantitative analysis of a simple random sample
of 150 households. The study shows that extension contacts, access to credit, farmer group
membership and experience with improved maize varieties favor farmers’ access to formal seed
maize channels are the most important factors. However, distance to output market, distance to
extension service and transaction costs negatively influenced participation in the formal seed
maize channel. Addressing these constraints will enhance smallholder farmers’ access to
improved maize varieties but will require greater public and private sector interventions
especially in the case of provision of extension services. Agricultural extension should not only
play a role in disseminating information and seed technologies but also stimulate the emergence
of agricultural innovation systems.
Key words: Maize seed, farmer access, semi-arid areas, Kenya, innovation systems
112 aGRO 2011 Biennial Conference E3026. FACTORS AFFECTING LOAN REPAYMENT PERFORMANCE OF
SMALLHOLDER FARMERS IN EAST HARARGHE, ETHIOPIA
Haile, Million Sileshi 12*3,4 Rose Nyikal1 and Sabina Wangia1
1
University of Nairobi, Department of Agricultural Economics, Kenya, Email: 2University of
2
Haramaya University, School of Agricultural Economics and Agribusiness, Ethiopia
Abstract
This paper examined the determinants of loan repayment performance among smallholder
farmers in East Hararghe zone, Ethiopia, specifically Kombolcha and Babile districts. In the
study area, the Regional Government through Oromiya Saving and Credit Shear Company and
Non-Governmental organizations have extended credit facilities to farming households to narrow
the gap between the required and the owned capital to use improved agricultural technologies
that would increase production and productivity. However, there is serious loan repayment
delinquency in the study area, which discourages the rural finance from promoting and extending
credit. A structured questionnaire was used to gather information from 140 smallholder farmers,
who received loan from formal financial institution, using the multistage sampling technique.
The study revealed that of the total sample households 71.43 percent and 28.57 percent
households were partial loan defaulters and complete non-defaulters, respectively. The two-limit
tobit regression model indicated that agro ecological zone, off farm activity and technical
assistance from extension agent, positively influenced the loan repayment performance of
smallholders farmers while production loss, informal credit, social festival and loan income ratio
negatively influenced the loan repayment of smallholder farmers at less than five percent level
of probability. Based on the findings policy implications were drawn for improving loan
repayment performance and sustainability of credit services and institutions in the study areas.
Key words: Loan repayment, determinant, smallholder farmers, and two - limit tobit model
113 aGRO 2011 Biennial Conference E3038. COST EFFICIENCY ESTIMATES OF DAIRY COW FARMS IN KENYA’S
EASTERN CENTRAL HIGHLANDS
Mugambi, D. K.1, 2*, Wambugu, S.K.2, Gitunu, A.M.M3, Maina, M4
1
Ministry of Livestock Development, P. O. Box 38-60602, Kianjai, Kenya 2Department of
Agribusiness Management and Trade and 4Department of Agricultural Science and Technology,
Kenyatta University, P. O. Box 43844, Nairobi, Kenya. 3Kenya Agricultural Research Institute,
Embu.
Abstract
The objective of this study was to determine the cost efficiency of dairy cow farms in the eastern
central highlands of Kenya. A stochastic frontier cost function was estimated using the maximum
likelihood estimation (MLE) technique. The data was collected through a cross-sectional survey
from 135 farms in the study area in 2010. The sample size was arrived at using the Fischer’s
formula. The MLE results revealed that the prices of roughage feeds and labour were the major
factors associated with the total cost of dairy cow enterprises, both being significant at p<0.01.
Results showed that farms were operating at diseconomies of scale and that roughage feeds could
be substituted with either mineral supplements or labour to reduce costs. The mean farms cost
efficiency index was 4.4%. Among the parameters hypothesized to affect efficiency, only a
farmer’s membership to a group and size of owned land were statistically significant. The
average cost per farm was Ksh. 551 while the milk revenue was Ksh.365. It was concluded that
the main challenges to dairying were the cost of feeds and the small land sizes owned.
Possession of the necessary knowledge on cattle dairying was found to be low. It was
recommended that land policy be put in place to address both land sub-division and its
consolidation. Policy and research interventions to ensure Kenyan milk becomes accessible
through cost leadership are recommended.
Key words: Cost efficiency, cost function, milk, cost leadership, fodder productivity
114 aGRO 2011 Biennial Conference E3039. THE ROLE OF EFFICIENCY IN REDUCING THE COST OF MILK
PRODUCTION IN KENYA
Mugambi, D. K.1, 2*, Wambugu, S.K.2, Gitunu, A.M.M3, Maina, M4
1
Ministry of Livestock Development, P. O. Box 38-60602, Kianjai, Kenya; 2Department of
Agribusiness Management and Trade and 4Department of Agricultural Science and Technology,
Kenyatta University, P. O. Box 43844, Nairobi, Kenya. 3Kenya Agricultural Research Institute,
Embu.
Abstract
The objective of this study was to determine the relationship between efficiency and cost of milk
production in Kenya. Data were collected from a sample of 135 farms in Embu and Meru
counties through a cross-sectional survey in 2010. The sample size was arrived at using the
Fischer’s formula. Data was analyzed using the FRONTIER 4.1c econometric model to obtain
both the technical and cost efficiencies. Derived mathematical formulae were used to obtain the
potential cost reductions. Technical and cost efficiencies were calculated to be 0.837 and 1.044,
respectively. Assuming obtained efficiencies were to attain the frontier target, mathematical
computations indicated that cost per litre of milk could be reduced from the observed Ksh. 38.5
to Ksh. 30.9. Conclusions were that dairy animals were overstocked, underfed, and farm labour
under-utilized. Results further showed that efficiency could be increased through increase in
quality and number of livestock extensionists, encouraging farmer group membership, and
having bigger farmlands. It is recommended that the policy be formulated to address land
ownership (size), number of extension staff, and the factors that lead to high dairy input costs. It
is further recommended that farmers consider enterprise specialization in order to optimize on
dairy, join groups, and seek extension services when needed. Researchers should develop options
for nutritious fodder and forage plants that could do well across varying agro-climatic zones.
Key words: Technical and cost efficiencies, production cost, Livestock
115 aGRO 2011 Biennial Conference E3021. FACTORS INFLUENCING PARTICIPATION IN MICROFINANCE SERVICES:
THE CASE OF SMALLHOLDER FARMERS IN NYAMAGABE DISTRICT, RWANDA
Mutamuliza Eularie 1, Nyikal R.A1, Mbogoh S.G.1
1
University of Nairobi, Department of Agricultural Economics, College of Agriculture and
Veterinary Sciences. P.O. Box 29053 - 00625, Nairobi, Kenya
Abstract
Many smallholder farmers in Rwanda depend on agriculture directly or indirectly for their
livelihood, but often lack self-financing for their activities. Like in many other parts of the world,
such farmers are excluded from participation in traditional commercial banking services.
Evolution of microfinance organizations therefore seems handy. Despite the increasingly
important roles assigned to microfinance services in poverty reduction in Nyamagabe District,
little is known about their contribution to the income and livelihood of the beneficiaries in
Rwanda in general and in the smallholder farming sector in particular. The drivers to farmers’
participation in the services are also not strictly known. This study sought to assess the factors
influencing smallholder farmers’ participation in microfinance services. The analysis is based on
household data collected from a survey of 240 households in three sectors of Nyamagabe District
in March 2011. Logistic model and Descriptive statistics were used to analyze the data. The
results from Logistic model shows that age, farm labor participation, savings, annual total assets,
annual interest rate and source of income influenced the smallholder farmers’ decision to
participate in microfinance services. The study finds out that participation in microfinance
services should change the smallholder farmers’ lives. This study also will help policy makers to
take appropriate actions towards up-scaling or reforming the rural financial system. The study
recommended that public and private sectors will need to support microfinance institutions both
in urban and rural areas. The emphasis should be put on the level of savings mobilization and
reduction of annual interest rate, so that smallholder farmers could have a chance to participate in
well functioning microfinance services for increasing their incomes and agricultural productivity.
There is a need also to encourage the young people to participate in microfinance services for
improving their welfare.
Keywords: Microfinance services, Participation, Credit access, Logistic Model, Rwanda
116 aGRO 2011 Biennial Conference E3027. QUALITY FACTORS AFFECTING MAIZE MARKETING BY SMALL SCALE
FARMERS IN WESTERN KENYA
Ogemah, V.K.1, Mukhwana, E. J.2, Odera, J.T.2, Nyando V. V. 1, and Kuloba, M.M.2
1
Masinde Muliro University of Science and Technology
2
Sustainable Agriculture Centre for Research Extension and Development (SACRED)- Africa
Abstract
Small scale farmers in Western Kenya are faced with numerous challenges in the marketing of
their produce resulting in them not being able to meet market requirements or earning less than
expected from their produce. A maize marketing project implemented by SACRED Africa
between 2002 and 2007 in Bungoma, Vihiga, Butere-Mumias and Siaya districts was developed
with the objective of identifying factors that limit small scale farmers’ participation in the formal
maize market among others. In the course of the project, data was collected from cereal bank
groups’ members within the project area using structured questionnaires. A total of 280 farmers,
20 from each of the 14 cereal banks were interviewed. In addition, interviews were also
conducted with key informants from National Cereals Produce Board, Ministry of Agriculture in
the project area and Kenya Agricultural Commodity Exchange. Based on the data collected,
several quality factors were identified as limiting the farmers’ ability to effectively participate in
the formal maize market. It was also established that many farmers were unaware of the standard
quality requirements of the formal marketing and this contributed significantly to their inability
to meet them. This paper discusses the various quality factors and conditions in which they
occur. Possible interventions that can be effected by the farmers and other stakeholders are
proposed.
Key words: maize, post-harvest , quality, marketing, cereal bank
117 aGRO 2011 Biennial Conference E3028. FACTORS INFLUENCING THE ADOPTION OF MAIZE STORAGE
TECHNOLOGIES IN MALAWI
D. Kachingwe-Phiri*, C. Ackello-Ogutu1 and F.I. Mugivane1
1
Department of Agricultural Economics, University of Nairobi, P.O. Box 29053 – 00625,
Nairobi, Kenya.
Abstract
The widespread post harvest maize losses experienced in Malawi have been mostly attributed to
the Larger Grain Borer (LGB) (Prostephanus truncates). The government of Malawi introduced
various maize storage technologies to minimize the post harvest maize losses. However, the
adoption of the modern maize storage technologies remains low. The purpose of this study,
therefore, was to analyze factors influencing the adoption of maize storage technologies in
Malawi. Binary logit model was fitted to data obtained from household survey conducted in
2010 in Zomba District, Malawi. Regression results indicated that adoption of the modern gas
hermetic bag (and related modifications) was significantly influenced by location of farmer,
distance to the market, farmer field school training, off farm income, extension and perceptions
about the efficacy of the storage technology regarding security against maize theft. The results
also showed that when compared with farmers using traditional maize storage technologies,
farmers using modern gas hermetic bag realized higher gross margins. The study recommended
that, among other things, government should promote development of maize storage
technologies taking into account location of farmers. Extension service delivery should be
prioritized. Farmer perceptions on technology attributes should be given proper attention when
designing maize storage technologies. Farmers should be encouraged to use modern technologies
in view of their (modern technologies) economic superiority over traditional technologies.
Key Words: Maize storage technology, Post harvest maize losses, Larger Grain Borer,
Adoption, Logit, Zomba, Malawi
118 aGRO 2011 Biennial Conference E3030. DETERMINANTS OF CHOICE OF COMPLIANCE ARRANGEMENTS WITH
GLOBALGAP STANDARDS AMONG FRENCH AND SNOW PEAS FARMERS IN
CENTRAL AND EASTERN KENYA
Otieno1*, P.S., J. Mburu1, R.A. Nyikal1, R. Owuor1
1
*
Abstract
Compliance with GlobalGAP standards is considered as the only option through which
smallholder farmers can access competitive export produce market. However, very little is
known about the determinants of farmers’ choice of any of specific compliance arrangements.
The aim of this study was to determine and discuss the factors that influence farmers’ decisions
when selecting specific compliance arrangements in Central and Eastern Kenya. One thousand
and four hundred smallholder fresh producers were randomly sampled and interviewed. Using
multinomial regression analysis, the study found income and distance to market as important
determinants of compliance arrangements chosen by farmers, though their direction and
significance of influence differed in specific study areas and the compliance arrangement under
consideration. The paper derives important policy implications for enhancing compliance of
GlobalGAP standards and thus increased access to export market for fresh produce which could
ultimately improve livelihoods of farmers in the study areas.
Keywords: French beans, Snow peas, Global Standards, Market access
119 aGRO 2011 Biennial Conference E3036. ADDRESSING FACTORS THAT AFFECT EFFICIENCY OF TRAINING AT
PHD LEVEL: A STUDY ON ACHIEVEMENTS OF INITIATIVES TARGETING PHD
LEVEL TRAINING
Wahome R.G.1, P.N., Mbugua1, L. Bebora1, S. Shibairo2, and W. Kogi-Makau3
1
3
Department of Food Science and Technology, University of Nairobi
2
Abstract (E3036)
A questionnaire developed and pretested to document and assess knowledge, attitudes and
practices on training at PhD level was administered to respondents randomly selected from
among the administrators, academic staff, PhD students and recent PhD graduates of three
colleges of the college of Agriculture and Veterinary Sciences (CAVS), the College of
Biological and physical Sciences (CBPS), the College of Education and External Studies (CEES)
and the College of Humanities and Social Sciences (CHSS) of the University of Nairobi. The
numbers of respondents were weighted in favour of CAVS and CBPS which formed the core
thrust of the project. Individual interviews were held with respondents through enumerators
supervised by project team. The study demonstrated large variation in attitudes, knowledge and
practices in the training of the PhD students. Key among them were student tracking,
supervision, PhD Examination, PhD Taught courses and PhD student networking. Awareness of
the weaknesses has significantly increased and response to efforts to enhance efficiency has been
very positive.
Key words: Agriculture PhD Training, supervision, attitudes, efficiency,
120 aGRO 2011 Biennial Conference E3032. ASSESSING THE FEASIBILITY OF BLENDED LEARNING: UNIVERSITY OF
NAIROBI STUDENT PERSPECTIVES
1
1
2
Anderson Wangia Victoria and Sabina Wangia2
University of Kansas Medical Center School of Nursing, Kansas City, Kansas
Department of Agricultural Economics University of Nairobi
Abstract
Technological advances such as computers, mobile technology, the Internet have influenced a
wide variety of areas including education. Blended learning is an innovative approach of learning
that is possible because of these advancements. It educates students by combining traditional
classroom instruction with the use of information technology (IT) to support the learning
process. This use of IT to support the learning process is referred to as e-learning. The
adoption of blended learning in a circumstance where the curriculum is entirely classroom-based
requires determining feasibility. Feasibility assessment can involve all stakeholders or subsets of
stakeholders. Students are important stakeholders because they are the ultimate benefactors of
the educational process. The objective of the pilot study was to assess the feasibility of
combining traditional classroom-based instruction of Agricultural Economics courses with elearning. A survey administered to University of Nairobi students and lessons learned from the
University of Kansas informed the survey design and study. An online survey was developed and
administered to Agricultural Economics students. Instructions for completing the survey and
definitions were included. The data was analyzed in SPSS with focus on descriptive statistics and
qualitative data analysis. Results showed that students agreed blended learning would improve
their learning. Ninety percent of the survey respondents indicated that blended learning was their
preferred way of learning. They identified challenges and advantages of adoption, noting their
expertise with technology. They identified a variety of ways they use their computers with 90%
of the students using their computers for Internet access. As technology continues to advance
educators have immense opportunity to adopt it to meet learning needs and challenges, to
improve learning outcomes and, to meet student expectations. The technology should be selected
to match needs and optimized for instructional quality.
Key words: teaching technology, classroom-based instruction, e-learning, blended learning
121 aGRO 2011 Biennial Conference E3033. IMPACT OF AGMARK’S PROGRAM OF STRENGTHENING AGRODEALERS
ON SALES OF FARM INPUTS IN KENYA
Wangia Sabina and James Mutonyi
1
AGMARK - Agricultural Market Development Trust is a Kenyan not-for profit organization.
Department of Agricultural Economics, University of Nairobi.
3
James Mutonyi AGMARK, Kenya
2
Abstract
The Agricultural Sector Development Strategy of the Ministry of Agriculture in Kenya and the
Comprehensive Africa Agricultural Development Program (CAADP) identified the pillar of
access to farm inputs and output markets as key to agricultural development. In support of this
Pillar, Agricultural Market Development Trust (AGMARK ) implemented an agrodealer
strengthening program from 2004 to 2010. The objective of the study was to assess the impact
of the AGMARK programme on sales of improved farm inputs to smallholders in Kenya. The
study used mainly secondary data from monthly, Mid-term and Final Reports for the Project
period. The study also used complementary primary data collected from consultative meetings
with two senior technical officers of AGMARK and interview of agrodealers using sms (in full))
and email, and structured questionnaires administered on face to face basis. The data collected
included number of trained farmers and agrodealers, volume of farm inputs and produce sales.
Data were analyzed using SPSS programme to generate means, modes, variances and trends. The
difference of means of volume of inputs produce sales before and after the project period was
analyzed and compared statistically. Three thousand (3,000) agrodealers and twenty five (25)
university student interns were placed in and exposed to farm inputs and output markets.
Trained agrodealers increased sales of inputs by over 100% between 2004 and 2010. Agrodealers
involved in marketing quality farm produce increased from 20% to 60%..Currently, 85% of the
trained smallholder farmers use improved farm inputs compared to 30% at the start of the
Project. The study concluded that AGMARK positively impacted on the sale of improved farm
inputs and consequently improved farm input market access, income levels among agro-dealers
and increased productivity for farms using purchased inputs. The end result was a multiplier
effect on improved livelihoods and food security in the project areas and Kenya at large.
Key words: Agrodealer, agricultural inputs /output, market access, productivity, livelihoods
GENDER, POLICY AND GOVERNANCE IN AGRICULTURE
123 aGRO 2011 Biennial Conference P4001. ESSENTIAL SERVICES PACKAGE OF SUPPORT TO IMPROVE
PRODUCTIVITY OF WOMEN SMALLHOLDER FARMERS IN KENYA
1
Hutchinson, M.J., 1Ambuko, J., 1Nyikal, R. and 2Ruto, G.
1
Kenya Professional Association of Women in Agriculture and Environment, P.O. BOX 23800606, Sarit Centre, Nairobi
Abstract
Smallholder farmers are responsible for 90% of the food grown in Africa and are the majority of
farmers in most developing countries with FAO estimating that at least 80% of rural smallholder
farmers worldwide are women. Despite their significant role in agriculture and household food
security, women farmers have not received the support they require to thrive and there is no
advocacy tool to guide governments and donors on the kind of minimum support women farmers
must receive if tangible success is to be expected of interventions. The Kenya Professional
Association for Women in Agriculture and Environment (KEPAWAE), on behalf of Action Aid
International (AAI), conducted desk study and field research in two of their Development
Initiatives (DIs) in Kenya (Tangulbei and West Region) and developed an Essential Services
Package (ESP). The ESP is as an advocacy tool to guide governments and donors in providing
basic core minimums for women farmers with the overall aim of enhancing women’s
productivity and ability to attain food security and sovereignty. The key essential services
identified in the study include access and control of land, inputs, extension and training, finance
and credit, research and technology, marketing services and water/irrigation. These essential
inputs and services were ranked differently by women farmers in the two regions of study. The
ranking of the different services seemed to have been influenced by the differences in agroecological dynamics, socio-cultural and economic differences between the ethnic groups
represented. The study concluded that in order to achieve desired development goals, it is
imperative that special attention in providing essential services to poor women farmers be taken
seriously, if the negative trends in development of emerging economies are to be reversed.
Key words: advocacy, development, essential services, gender, productivity, smallholder
agriculture, women
124 aGRO 2011 Biennial Conference P4002. DOES KENYA’S VISION 2030 CAPTURE THE GENDER DIMENSION IN THE
AGRICULTURAL SECTOR?
Hutchinson, M.J. and Kabira, W.M.
Africa Women Studies Centre, University of Nairobi, P.O. Box 30197-00100, Nairobi
Abstract
The Vision 2030, Kenya’s long-term development blueprint, identifies Agriculture as the
mainstay of the Kenyan economy, representing 24% of GDP and forming a key sector in the
economic pillar. In the Vision, the Government embraces gender mainstreaming for sustainable
development. Analysis of the extend Gender concerns are truly taken on board has not been
interrogated. The main objective of the study was to conduct a gender audit of the policy and
program plan for the agricultural sector of Vision 2030. Desk studies, questionnaires,
workshop/seminar presentations and focused group discussions were used to identify gaps and
propose improvements in the proposed performance indicators that would capture the gender
dimensions. Gender policy analysis tools were developed and shared with women scientists at
the University of Nairobi, and reviewed by teams of experts. The tools were tested with women
and men farmers from the Mwea Irrigation Scheme, representing a key flagship project in the
policy document. The findings of the study indicate that while attempts have been made to
mainstream gender, there are several gaps, even in the indicators used to capture performance
targets. The study underscores the importance of adequately involving men and women in
policies/ programs/ project design, development, implementation as well as monitoring and
evaluation in order to come up with strategic interventions in the key sector of agriculture.
Key words: Vision 2030, Gender, Agriculture Sector, Gender Policy Analysis Tools
125 aGRO 2011 Biennial Conference P4003. HORTICULTURAL ELECTRONIC EXPORT CERTIFICATION SYSTEM TO
FACILITATE TRADE
Mbarani .D, Syanda J., Gachamba S.1, Ulare .P1, Wambugu .N.1, Kimani .E.1, Ntoyai . N.1,
Kigamwa. J.1, Moret. .L2, Karanja .P.3 Ngige .J.4 and Mbithi .S.5
1
Kenya Plant Health Inspectorate Service (KEPHIS), P.O. Box 49592-00100, Nairobi, Kenya.
Ministry of Economic Affairs, Agriculture and Innovation, P.O. Box 20401, 2500, EK, The
Hague, The Netherlands.3Embassy of the Kingdom of the Netherlands, Office of the Ministry of
Economic Affairs, Agriculture and Innovation, P.O. Box 41537, Nairobi, Kenya.5Fresh Produce
Exporters Association of Kenya. 4The Kenya Flower Council, P.O. Box 56325-00200, Nairobi,
Kenya.
2
Abstract
The paper reports the initiative of KEPHIS, The Netherlands and horticulture industry
stakeholders in the development of an Electronic Certification System (ECS) for horticultural
export produce. The horticultural industry in Kenya has shown tremendous growth over the last
three decades generating in 2010 an equivalent of Kshs. 78 billion in foreign exchange through
horticultural exports. Its export process requires routine issuance of 146,000 of phytosanitary
certificates annually. The introduction of e-certification at KEPHIS would greatly enhance the
capacity of phytosanitary inspectors by freeing a significant amount of the time spend on issuing
paper certificates to concentrate more on actual inspections. Therefore, ECS was created in order
to introduce an electronic certification process that is more convenient and cost effective. The
ECS was based on a system created in The Netherlands for E-certification (Client), using
Information Engineering techniques including the redesign of business processes. The ECS uses
direct trader input for the capture of data for applications, complying to the relevant standards
recommended by International standardization bodies (e.g. UNCEFACT, IPPC). The
applications are processed and after approval a phytosanitary certificate, in both electronic and
paper copy, is issued. This culminated in the official launch of the ECS on 19th April 2011.
Currently over 60 % of active exporters are using the system. The paper describes efforts
towards integrating the ECS into horticulture sub-sector business operations through Business to
Government solutions (B2G). This will enhance plant protection and efficient management of
the export certification process to the benefit of both exporters and KEPHIS by reducing time
spent in processing of Phytosanitary certificates, improve documentation logistics, re-use
information and facilitate negotiations for pre-clearance procedures.
Key words: Horticulture, Kenya, Business process redesign, Electronic Certification System,
Phytosanitary certificates, ECS, Business to Government.
126 aGRO 2011 Biennial Conference P4004. BIOBIBLIOMETRIC STUDY OF PROFESSOR WANGARI MUTA MAATHAI
Nyang’anga Thadias Hillary1 and Gatero George2
1
2
Jomo Kenyatta University of Agriculture and Technology
Abstract
Professor Wangari Muta Maathai was the 2004 Nobel peace prize winner because of her
environmental conservation activities. She is the founder of The Greenbelt movement, a
nongovernmental organization which she has used to champion several environmental
conservation activities. To date, she is still an ambassador of peace through her environmental
activities. However, not all information about Professor Wangari Maathai had been documented
in regard to environmental conservation. Interested parties did not know the philosophy and
purpose driving Professor Wangari Maathai. The focus of this study was to examine her
philosophy, focus and approaches and contributions in her long life dedication to environmental
conservation. The methodologies used were a bibliometric study, content analysis and
questionnaires. The study found out that Sensitization, mobilization, whistle blowing, financial
support, coordination, leadership and formation of organization as some of her key roles. It also
showed that love for the environment, gratitude and respect for the earth resources, self
empowerment and self betterment and the spirit of service and voluntarism as the social belief
which she held. In addition, poverty, clean water scarcity, firewood scarcity, need for clean and
healthy environment and the shift from traditional economy to money economy formed her
social concerns to environmental conservation. For her to have achieved her goals, she
collaborated with individuals and institution through chance, acuity, interest and leadership
collaborative methods which offered various support including finance, mobilization, exposure,
office space, forum for expression among others. Some of the results achieved include saving
Uhuru Park, Karura forest, Jevanjee gardens, and Mau complex, 402 publications, various
awards at local, regional and global level, Millions of trees planted and an enlightened Kenyan
population on environmental conservation. In addition, the trend of publications of and about
Prof Maathai was established.
127 aGRO 2011 Biennial Conference P4005. AFRICAN DRY LAND ALLIANCE FOR PESTICIDAL-PLANT
TECHNOLOGIES (ADAPPT): A network for optimising and promoting pesticidal plants’
use for food security and poverty alleviation in Africa.
1
Ogendo, Joshua O
1
ADAPPT Country Coordinator, Kenya & WP 4 Leader. Dept. of Crops, Horticulture and Soils,
Egerton University, P.O. Box 536- 20115 Egerton, Kenya
Abstract
The ADAPPT Network seeks to strengthen scientific and technological capacity of African
nations to optimally exploit pesticidal plants and promote their use for agricultural development
and poverty alleviation. The ADAPPT Kenya Chapter was launched in July 2010 at Egerton
University and currently boasts of over 50 members drawn from local universities, KARI,
NGOs, Government agencies, Seed companies and Community initiatives. The network will
facilitate the development and optimisation of appropriate, cost effective and environmentally
benign agricultural technologies that are based on indigenous pesticidal plant materials for insect
pest management and ecto-parasites control in smallholder agriculture across African dry lands.
Ultimately this project aims to reduce the high level of rural poverty by making agriculture and
animal husbandry more competitive, increasing food security and raising poor farmers’ incomes
by cost effectively increasing crop yields, reducing storage loss and protecting livestock. The
ADAPPT Network addresses the following specific objectives, namely (a) Establish, consolidate
and expand a regional network to research, exploit and optimise the use of pesticidal plants; (b)
Provide a forum for widely raising awareness about pesticidal plant use; (c) Create an
environment for cross-training and skills-transfer through individual and institutional capacity
building; and (d) Develop policy guidelines to ensure validated marketing and promotion of safe
and effective plant-based pesticides. The ADAPPT Network activities have been divided into six
work packages (WPs), namely; WP1: Management, Monitoring and Evaluation of Project; WP2:
Development and establishment of ADAPPT network [www.nri.org/adapt]; WP3: Develop
instruments for collaborative research through capacity building and training; WP4:
Dissemination of outputs and promotion for raising awareness and improving access to
information; WP5: Development and promotion of sustainable production of botanical pesticides
through propagation and conservation; and WP6: Commercialisation and marketing. Progress on
ADAPPT Network activities, Kenya Chapter Action Plan, ADAPPT international conference
and new platform, the Pesticidal Plant Technologies Network (PEPTEN) are presented.
Key words: Pesticidal plants, poverty alleviation, biodiversity conservation, scientific
networking
128 aGRO 2011 Biennial Conference P4006. BRIDGING PHYTOSANITARY CAPACITY THROUGH THE CENTRE OF
PHYOSANITARY EXCELLENCE (COPE)
Kimani E1., J. Kigamwa1, F. Chege2 and J.Muthomi3
1
Kenya Plant Health Inspectorate Service (KEPHIS), P.O. Box 49592-00100, Nairobi. Kenya.
CABI Africa, P.O. Box 633, 00621, Nairobi, Kenya.
3
University of Nairobi, P.O. Box 29053-00625, Kangemi, Nairobi, Kenya.
2
Abstract
This paper reviews efforts made towards addressing phytosanitary concerns in Africa through
training and pest risk analysis networks in the Centre of Phytosanitary Excellence (COPE).
COPE was established through a project initially supported financially by Standards Trade and
Development Facility (STDF), International Plant Protection Convention (IPPC), National Plant
Protection Service (NPPS) of the Netherlands and KEPHIS with partners such as Africa Union –
InterAfrica Phytosanitary Council (AU-IAPSC), University of Nairobi, CABI and Ministries of
Agriculture in Zambia, Tanzania and Uganda among others. COPE was launched officially by
the Assistant minister for Agriculture, Mr. Kareke Mbiuki as a centre on 27th October 2010 at the
Kenyatta International Conference Centre, Nairobi, Kenya. Since March 2011, COPE has
undertaken two trainings and a total of 31 students drawn from both local and regional public
and private sectors have been trained on phytosanitary standards and pest risk analysis. For the
sustainablity, the centre charges training fee which is met by either the trainee or the sponsors.
COPE hopes to bridge phytosanitary capacities in African countries for effective management
and co-ordination of phytosanitary systems at national and regional level. This paper describes
training achievements in the last three years and efforts in creating pest risk analysis networks
that are essential for making informed phytosanitary decisions.
Key words: COPE, IPPC, Phytosanitary, Training and Pest Risk Analysis
129 aGRO 2011 Biennial Conference POSTER PRESENTATIONS
ARBUSCULAR MYCORRHIZAL FUNGAL COMMUNITIES IN SOILS UNDER
SWEETPOTATO IN WESTERN KENYA.
Kundu, C. A.1, 2, 3, Karanja, N. K.2, Jefwa, J.3, Ndolo, P. J.1, Mwangi, E.2 And Simwa, S1.
1
Kenya Agricultural Research Institute- Kakamega, P.O. Box 169-50100, Kakamega
2
University of Nairobi, LARMAT, P. O. Box 29053-00625, Nairobi
3
Tropical Soil Biology and Fertility Institute of CIAT, P. O. Box 30677-00100, Nairobi
Corresponding author E-Mail: [email protected]
Abstract (L1002)
Arbuscular mycorrhizal fungi are of considerable interest because they have the ability to form
symbiotic associations with several crop species. In this work, the occurrence of arbuscular
mycorrhizal species diversity in soils from two districts in Western Kenya was evaluated in trap
cultures. Rhizosphere soil samples were collected from four orange fleshed sweetpotatoes
(OFSP) varieties in two districts. A total of forty eight samples were collected, twenty four
samples from each district and six samples for each of the four OFSP varieties. Previous crop
grown was also noted. The soil samples were analyzed chemically for pH, organic matter,
available phosphorus (P) and total nitrogen (N). Spore count for the samples was done before
setting up trap cultures. Trap cultures were thereafter established using the four OFSP varieties,
Allium porrum L, Sorghum bicolor and Glycine max. The traps were grown for 150 days under
greenhouse conditions, when the colonization, spore density and species diversity were assessed.
Three genera Scutellospora spp, Glomus spp and Gigaspora spp were identified. Scutellospora
spp was the most abundant genus with a spore abundance of 68 spores/25g of soil while
Gigaspora spp the least abundant with 27 spores/25g of soil. It was also indicated that
colonization rates varied between the trap crops used. The frequency and intensity of
colonization (56.7% and 32% respectively) was highest in Allium porrum L, and lowest in
sweetpotato (20% and 12%). Research directions are needed to increase the understanding of
these symbiotic mycorrhizal associations in tropical cropping systems and to understand their
benefits in crop production.
Key words: Arbuscular mycorrhizal fungi, trap cultures, colonization, frequency, intensity.
131 aGRO 2011 Biennial Conference EFFECT OF NUTRITION ON INFECTIVITY OF THE NEMATOPHAGOUS THE
FUNGUS Pochonia chlamydosporia ON NEMATODE EGGS
Mutua, G.K2., Kimenju, J. W2., E. Ward1, , R. H. Manzanilla-López1, B. R. Kerry1, & P. R.
Hirsch1.
1
2
Plant Pathology and Microbiology Dept., Rothamsted Research, Harpenden AL5 2JQ, UK
Department of Plant Science & Crop Protection, University of Nairobi.
Abstract (L1023)
Effective establishment of microbes applied to soil often requires addition of an exogenous
nutrient source to overcome competition from the resident microflora. However, readilyavailable nutrients may compromise the parasitic ability of facultative microbial parasites added
as biological control agents. A study to investigate the role of nutrition in regulating the
switching from the saprotrophic to the parasitic phase of nematophagous fungus Pochonia
chlamydosporia, was undertaken. Improvements were made to a bioassay to assess the
parasitism of P. chlamydosporia on eggs of Meloidogyne javanica and Globodera pallida under
varying concentrations of exogenous nutrient source (Yeast extract medium). Meloidogyne
janica eggs obtained infected tomato plants were adjusted to 1000 eggs ml-1 and inoculated with
sterilised yeast extract medium (YEM) and 2.75 x 104 ml-1 P. chlamydosporia conidiospores in
sterilised distilled water to a volume of 10 ml. The experiment constituted of 2 controls being
0.0125% YEM (no fungus) and Water (no fungus) plus the 3 media (0.00625% YEM, 0.0125%
YEM and Water) by 6 fungal isolates. Significant differences (P<0.001) were observed on the
influence of the media on egg parasitism of M. javanica and G. pallida eggs, respectively with,
egg parasitism being lowest at 24 hours and highest at 48 hours in all media. The YEM media at
both concentrations stimulated higher infection rates on both Meloidogyne and Globodera eggs
compared to the water medium. Compared to M. javanica eggs, higher infection proportions on
G. pallida eggs were observed across all the media demonstrate host preferences among the
isolates. Molecular techniques used to assess variation in P. chlamydosporia isolates, including
analysis of the VCP1 gene egg infection showed this gene to be highly conserved. Further,
expression of the VCP1 gene was up-regulated in media containing 2% glucose and suppressed
in nitrogenous media.
Keywords: Globodera; Meloidogyne; Parasitism; Pochonia
132 aGRO 2011 Biennial Conference DIVERSITY OF PLANT PARASITIC NEMATODES AND BACILLUS SUBTILIS
AFFECTING COMMON BEAN (PHASEOLUS VULGARIS L.) IN EMBU KENYA
Wepukhulu N. Miriam, John Kimenju and Beatrice Anyango
Department of Plant Science and Crop Protection, University of Nairobi. P.O Box 29053-00625,
NAIROBI
Abstract (L1038)
Plant parasitic nematodes cause estimated US $100 billion damage to agricultural crops. They
are among the pests that threaten bean production by smallholder farmers in Kenya. The study
sought to determine the presence of plant parasitic nematodes in Embu Kenya and different
management techniques including strains of Bacillus subtilis, and soil fertility improvement by
use of manure and inorganic fertilizer (TSP). The experimental set up included control plots with
no soil amendment. The experiment was laid in a completely randomized design with 4
replications. Plant parasitic nematodes were isolated from soils by the modified baermanns
technique while Bacillus subtilis were isolated using the procedure by Racke and Sikora. The
Data was subjected to analysis of variance using general statistical package for least significant
differences. Rotylenchus and Meloydogyne were among the most abundant nematode genera in
soils from Embu with 20% and 15% of the total nematodes respectively. Bacillus subtilis
combined with manure led to the highest (89%) reduction in plant parasitic nematodes. There
were significant (P<5) differences among the treatments with the control having the highest
galling index (4.5) on bean roots. B. subtilis and manure led to the least damage to bean roots in
the on farm experiments with galling indices of 1.6 and 1.8 respectively and contributed to the
effective control of Meloydogyne spp.
Key words: Manure, Rotylenchus Meloydogyne.
133 aGRO 2011 Biennial Conference SUBTHEME TWO
PARTICIPATORY VARIETY SELECTION OF DROUGHT TOLERANT DRY BEAN
GENOTYPES IN MWEA, KIRINYAGA SOUTH DISTRICT OF KENYA
Aufa Munyasa, J., Kabutbei, J.I., Chemining’wa, G.N., Kimani, P.M., Mburu, M.W. and
Nderitu, J.H.
Abstract (C2004)
A key agronomic strategy to enhance dry bean productivity in drought prone areas of Kenya is to
develop and deploy drought tolerant varieties. Dry bean nurseries in the national research
institutions within the eastern Africa region hold many drought tolerant genotypes whose impact
has not been felt at the national level. The objective of the study was to introduce high yielding,
drought tolerant bean varieties to farmers in Mwea, Kirinyaga South district. Participatory
variety selection (PVS) trials were set up in Mwea for farmers to select preferred drought
tolerant dry bean varieties. Separate field experiments involving Mesoamerican (84) and Andean
(88) varieties, respectively, were set up under rainfed and irrigated conditions. Twenty seven
male and female farmers participated in the exercise using their own criteria. Researchers and
extension workers demonstrated the PVS process. Men and women used different coloured
ribbons to indicate preferred and rejected varieties. Key criteria used to select varieties were
grain yield, colour, drought tolerance, pest resistance, uniformity of maturity and growth habit.
Men preferred high yielding varieties irrespective of grain colour while women preferred
varieties with red grain. Men rejected climbing varieties as they considered them unsuitable for
intercropping with maize and preferred varieties with high shoot biomass for fodder. Preferred
genotypes included DMC 11-11, SEN 53, DSS 11-08, DRK 11-18, and those rejected included
GLP585, KAT B1, DSS 11-03, and GLP92. This study shows that farmers’ criteria for selecting
drought tolerant varieties overlap with those of scientists, though with some exceptions. Gender
differences noted in the selection criteria emphasize the need to involve both men and women in
PVS.
Key words: Mesoamerican, Andean, dry bean, selection, criteria, drought, PVS
134 aGRO 2011 Biennial Conference PREHARVEST CULTURAL PRACTICES AFFECT POSTHARVEST QUALITY
ATTRIBUTES OF BANANA FRUITS, Musa spp
Ambuko, J1, Y. Sekozawa2, S. Sugaya2 and H. Gemma2
1
Department of Plant Science and Crop Protection, University of Nairobi, Kenya
2
Laboratory of Pomology, Graduate School of Life and Environmental Sciences
Tsukuba University, Japan
Abstract (C2006)
Preharvest factors including agro-ecological conditions, cultural practices and crop variety
selection greatly impact fruit quality potential at harvest and postharvest longevity. In this study,
quality attributes of banana fruits (Musa spp), cultivars ‘Williams’ and ‘Grande naine’ produced
under low chemical production system (LCPS) and conventional production systems (CPS) were
investigated. The fruits produced under the two production systems were evaluated for various
physicochemical attributes including peel hue angle, firmness, moisture content, starch, soluble
sugars and titratable acidity (TTA). Sensory evaluation by untrained panelists was done to
compare the organoleptic attributes of the banana fruits. The results showed that ‘Williams’
bananas from the LCPS had better eating quality as evidenced by higher soluble sugars, less
starch and lower flesh firmness and higher moisture content of the ripened fruits. ‘Grande naine’
bananas generally had higher levels of TTA compared to ‘Williams’ and in both cultivars LCPS
bananas had higher TTA levels compared to CPS bananas. These quality attributes were affected
by seasonal variability in climatic conditions. Sensory panelists did not clearly discriminate
between LCPS and CPS bananas but showed preference for ‘Williams’ bananas over ‘Grande
naine’ bananas. These results show that banana variety, cultural practices and harvest season
affect the banana quality attributes at harvest and affect the eating quality of the fruits.
Keywords: Musa spp. organic, conventional, production system, quality
135 aGRO 2011 Biennial Conference BREEDING FOR RESISTANCE TO COFFEE LEAF RUST (Hemileia vastatrix
BERKELY AND BROME) AND COFFEE BERRY DISEASE (Colletotrichum kahawae
WALLER AND BRIDGE) IN RWANDA
Bigirimana, J1*, Kiarie Njoroge2, J.W. Muthomi2, D. Gahakwa1, N.A. Phiri3 & E.K.
Gichuru4
1
Rwanda Agriculture Board, P.O. Box 5016, Kigali, Rwanda. 2Department of Plant Science and
Crop Protection, University of Nairobi, P.O. Box 29053, Nairobi, Kenya. 3 CABI Africa, P.O.
Box 633-00621, Nairobi, Kenya. 4Coffee Research Foundation, P.O. Box 4, Ruiru, Kenya
Abstract (C2007)
Coffee leaf rust (CLR) and Coffee berry disease (CBD) are the most important diseases limiting
coffee production in Africa. This study was undertaken to evaluate Rwandan coffee germ-plasm
for resistance to CBD and CLR. Screening for resistance to CBD was done using the hypocotyl
inoculation test while selection for resistance to CLR was carried out using the leaf disc
inoculation method. In the pre-selection for CBD resistance, a mean grade of infection was
calculated for each genotype in every replication and subjected to analysis of variance. Highly
significant differences (p < 0.001) were observed between genotypes with regard to CBD
resistance indicating the presence of genetic diversity in the germplasm collection. Commercial
cultivar “BM 139” along with introductions such as Locale Bronze, Ke 5, Matinho, Blue
Mountain Guatemala, CIFC 8224 and Catimor T8663 showed resistance to CBD. In addition,
Catimor T8663, Selection 5A, Selection 6 and CIFC 8224 were highly resistant to CLR.
Percentage infected discs, days to sporulation and days to 50% sporulation were positively
correlated except for days to sporulation and the percentage sporulating disc where the
correlation was low and non significant. Cultivar BM 139 may be improved for resistance to
CLR by backcross breeding using one of the CLR resistant accessions such as Catimor
T8663.The study indicated that CIFC 8224 and Catimor T8663 introductions are resistant to both
CBD and CLR and they should be further tested for yield, cup quality and adaptability in varying
environmental conditions.
Key words: Coffee, coffee berry disease, leaf rust, resistance
136 aGRO 2011 Biennial Conference SOIL FERTILITY STATUS AND NODULATION OF SELECTED LEGUMES IN
FARMERS’ FIELDS IN SOUTH-EASTERN KENYA
Chemining’wa, G.N., Wahome, P.K. and Muthomi, J.W
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 2905300625, Nairobi
Abstract
(C2100)
A field study was conducted to determine the soil fertility status and root nodulation of selected
legumes in farmers’ fields in upper and lower midlands agro-ecological zones (AEZ) of southeastern Kenya. Soils collected from 26 farmers’ fields were analyzed for soil pH, organic C, N,
P, K, Ca, Mg, Mn, Cu, Fe and Zn. Hyacinth bean, common bean (Phaseolus vulgaris), cowpea
(Vigna unguiculata), lima bean (Phaseolus lunatus), pigeon pea (Cajanus cajan), and green
gram (Vigna radiata) were planted in polythene bags containing sterilized river sand and
inoculated with soils from each AEZ and commercial rhizobial inoculants from the University of
Nairobi’s Soil Microbiology Laboratory. Seedlings were nourished using Broughton and
Dilworth N-free solution (Broughton and Dilworth 1971). Soil analysis results showed that soils
from farmers’ fields were deficient of N, P, Ca, Mg, Cu, Fe and Zn while K and Mn were
adequate. Soil pH ranged from 4.30 to 6.76 with 16 of the fields having pH below 6. Twenty five
sites were deficient in organic C. Nodulation of the selected legumes varied significantly across
AEZs while plants inoculated with commercial inoculants had higher nodule numbers and
nodule dry weights. However, inoculation with soils from collected from farm s in AEZ LM5
and LM3 soils increased tissue N in bean and cowpea plants significantly compared to the
commercial inoculants and the other soils. Soils in south eastern Kenya are low in fertility and
have variable capacity to support root nodulation of legumes.
Key words: nutrient, legume, nodulation, rhizobia, inoculation
137 aGRO 2011 Biennial Conference DETERMINATION OF PHYSICAL SUITABILTY OF ADVANCED DROUGHT
TOLERANT BEAN LINES FOR CANNING
Gathu, E.W1, E.G. Karuri1, P.M Kimani2 and P.K.Njage1
1
Department of Food Science, Technology and Nutrition, University of Nairobi
Department of Plant Science and Crop Protection, University of Nairobi. P.O Box 29053-00625
Nairobi, Kenya
2
Abstract (C2010)
Water uptake, percent volume increase and cookability after soaking are critical characteristics of
dry beans destined for the canning industry. New dry bean varieties released, should possess
good canning qualities to ensure uniform and complete water uptake in order to prevent further
expansion of beans in the can. This study determined the physical suitability of 8 new lines for
the canning process. These were randomly selected from 150 new advanced drought tolerant dry
bean lines. The physical attributes evaluated were the initial moisture content, bulk density, water
uptake, volume increase and cookability. The 8 bean genotypes of diverse market classes were
screened for water uptake by soaking the beans for 16 hours at room temperature (20.5 ± 0.5˚C).
The effect of soaking on volume change was determined by heptane displacement method in a
graduated container. Cookability was determined by the cooking time using a 25-well Mattson
pindrop cooker. All experiments were replicated three times. Mexican 142, a popular canning
bean variety, was used as the control. Analysis of 8 market classes showed that there were
significant differences (P< 0.05) in initial moisture content, bulk density and cooking time
among the genotypes. Initial moisture content varied from 10.00± 0.10 % (DNB 11-10) to
11.87± 0.12 % (Kenya Early); bulk density from 0.710± 0.003 g/cm3 (DNB 11-10) to 0.769±
0.003 g/cm3 (DSS 11-04) and cooking time from 30.31± 5.60 minutes (DPC 11-05) to 51.29±
13.6 minutes (DNB 11-10). However, there were no significant differences in water uptake and
volume change. All genotypes took up at least 90% water and qualify for canning purposes, with
six of them picking up water and cooking faster than the control.
Key words: Dry bean, canning, water uptake, cooking time, genotypes
138 aGRO 2011 Biennial Conference FERTILIZER AND MULBERRY VARIETY EFFECTS ON THE YIELD AND
QUALITY OF SILK
N.M. GATHUMBI1, J.M. KINAMA2, V. ADOLKA3 AND E. OBUTHO2
1
Horticulture Division, Ministry of Agriculture, PO Box 30028-00100, Nairobi, Kenya
2
Department of Plant Science and Crop Protection, University of Nairobi, PO Box 29053-00625,
Kabete, Kenya
3
International Centre for Research in Insect Physiology and Ecology (ICIPE), Kenya
Abstract (C2112)
Horticulture in Kenya has contributed significantly to the foreign exchange earnings as well as
enhanced small scale farmer earnings and food security. Research on relationships between
variety and fertilizer requirements will go along way in assisting farmers’ choice of appropriate
high yielding varieties and soil fertility management. The objective of the study was to
determine the effect of soil fertility and mulberry variety on cocoon and silk quality. An
experiment was conducted during the short rains of 2004/2005 and long rains of 2005, at
Kasarani and Thika using three mulberry varieties (Kanva, Noi (Thailand) and Embu (local
variety) commonly grown by farmers in silkworm rearing. The study compared the growth and
yield of three mulberry varieties. It further compared silk production using three varieties and
their quality response to inorganic fertilizer (NPK) and manure treatments. The treatments
applied were, nitrogen, phosphorus and potassium (50gm NPK) alone, 25gm NPK + 1kg
manure, 2kg manure alone, and control (no manure and no fertilizer). Mulberry growth
measurements taken were height of shoots, number of shoots, and number of leaves per shoot.
Leaf analysis was performed to compare leaf quality in terms of crude protein and crude fibre
from different varieties and treatments. Groups of fifty silk worms were reared with leaf
harvests from the different treatments. After spinning semi wet cocoon weight, dry weight, shell
weight, and pupa weight were taken. Silk quality was based on cocoon weight, shell weight,
length and weight of silk filament. The results showed that there were significant effects of
fertilizers and mulberry variety on mulberry growth performance, silkworm larva performance
and consequently on cocoon weight and filament length. Leaf growth, biomass, crude protein,
silk quality was significantly influenced by fertilizer application
Keywords: Mulberry variety, shoots, fertilizer and silk quality
139 aGRO 2011 Biennial Conference INSECT PESTS’ INCIDENCE AND DAMAGE ON Cleome gynandra IN DIFFERENT
AGRO-ECOLOGICAL ZONES
1
Hutchinson, M.J., 2Kipkosgei, L. and 3F.M. Olubayo
1,3
University of Nairobi, Department of Plant Science and Crop Protection; P.O. BOX 2905300625, Kangemi
2
Kenya Seed Company Ltd, P.O. BOX 553-30200, Kitale
Abstract (C2012)
African leafy vegetables (ALVs) have a potential of contribution to food security by providing
essential micronutrients especially among marginalized rural communities. ALVs, thought to be
more tolerant to biotic and abiotic stresses, have received little scientific inquiry on insect pest
dynamics, which would lead to low yields and poor quality under different agro-ecological zones
(AEZs). Insect pests affecting crops usually vary with The overall objective of this study was to
identify and determine the prevalence and nature of damage of insect pests on Cleome gynandra,
one of the most popular ALVs. The studies were conducted in Lugari and Keiyo districts of
Kenya falling under Upper Midland (Transitional) and Humid AEZs, respectively, during the
long rains and short rains of 2002. The crop was planted following farmers’ agronomic practices
on plots measuring 18 x 2m and replicated four times. The plants grown in the drier Lugari and
wetter Keiyo District were attacked by 8 and 7 insect species, respectively. Diamondback moth
(Plutella xylostella), African bollworm (Helicoverpa armigera), black bean aphids (Aphis
fabae), cotton aphids (Aphis gossypi) and Systates weevil (Systates pollinosus) attacked the crop
in both AEZs. Leaf roller (Sylepta derogate), cabbage sawfly (Athelia spp) and chafer grub
(Schizonycha spp) were detected at Lugari while cutworms (Agrotis spp), flea beetles
(Chrysomelidae spp),) and cucurbit ladybird beetle (Epilachna spp) were found attacking the
crop only in Keiyo district. Diamondback moth and aphids were more prevalent and caused more
damage in Lugari, especially during the short rains. Helicoverpa was slightly more prevalent in
Keiyo for a short period between 6-8 weeks after planting. There was no difference in prevalence
and severity of systates between the 2 AEZs. The study results indicate that insect pests caused
significant damage to Cleome gynandra and the presence and severity of damage varied with
AEZ and season.
Key words: African Leafy Vegetables, Cleome gynandra (cat’s whiskers), insect pests
140 aGRO 2011 Biennial Conference COMPARATIVE EFFICIENCY OF GLYPHOSATE AND HAND WEEDING ON WEED
IN MAIZE PRODUCTION
Ita, B.N1, Michieka, R2.W, Ariga, E.S2 and Muiru, W.M2.
1
2
Kenya Agricultural Research Institute, KARI, NARL, BOX 14733,00800 NRB
Abstract (C2014)
Weed management practices used by small scale farmers determine maize productivity. This
study was conducted in Kigumo district during the long and short rains in 2010 to compare
effectiveness of glyphosate and hand weeding on weed management in maize (Zea mays L.).
Treatments were two maize varieties DUMA SC41, DK8031 and three weed management
practices, glyphosate (zero tillage), hand weeding (conventional tillage) and no tillage (control).
Plots sizes were 5 x 3 m laid out in a randomized complete block design, replicated three times
with maize spaced at 75x30 cm. Glyphosate plots were sprayed five days prior to planting, hand
weeding and no tillage plots were dug and leveled using jembes. An area of 3 x1.5m in each plot
was used for data collection, weed count was done five times on monthly interval at 3 weeks
after planting (3WAP), 7WAP,11WAP, 15WAP and 19WAP. Biomass dry weight was achieved
by drying the weeds in an oven at 60 0 C for 72 hours. Gen stat computer software package was
used for data analysis, effects of weed management practices on weed counts, biomass, maize
grain yield were assessed by ANOVA, treatments means were separated by Student- Newman
Keuls Test. There was no significant difference at P < 0.05 in weed count between the two weed
management practices , hand weeding and glyphosate. There was no significant differences
between the two weed management practices in biomass, maize grain yield at P < 0.05, but the
two maize varieties significantly differed in grain yield. Although there was no significant
differences between the two weed management practices in biomass and maize grain yield,
glyphosate had lower weed biomass and higher maize grain yield than hand weeding, therefore a
better weed management practice.
Key words: Small scale farmers, weed management, maize productivity
141 aGRO 2011 Biennial Conference STUDIES ON INSECT PESTS AND DISEASES OF CHAYOTE, SECHIUM EDULE
(SWARTZ.) IN KENYA
Kahuthia-Gathu R1 and Maina Mwangi1
1
Kenyatta University, PO BOX 43844 00100 Nairobi
Corresponding author E-mail: [email protected]
Abstract (C2130)
The chayote, Sechium edule Sw., belongs to the family Cucurbitaceae. All parts of the plant can
be utilized including the fruit, seed, tuberous roots and young shoots. Yields of up to 1,500 fruits
per plant have been recorded. A study was conducted to investigate the pests that attack this
crop. Mature plants were observed for pest damage, punctured and wounded fruits were
harvested, placed in plastic containers and observed daily for larval and subsequent pupal
development. The pupae were harvested using forceps, placed in plastic vials and observed daily
for adult emergence. The emerged adults were identified, sexed and counted. Data was analysed
using SAS. The leaves were infested by sap sucking pests; thrips, Spider mites Tetranychus
ludeni, Cotton aphid Aphis gossypii, White flies Bemisia tabaci, brown bugs, leaf feeders;
Spodoptera species and coleopteran. The fruits were infested by fruit flies Dacus bivittatus and
D. ciliatus and two unidentified dipteran species. An average of seven fruit flies was collected
from each fruit. Fruit flies significantly reduced fruit yields and marketability; causing fruit rot
and deformation. The wounds caused by insects provided entry points for fungal pathogens. Fruit
fly larvae that came into contact with the fungus died. But those that developed within the fruit
and only came to the surface for pupation were able to pupate and emerge as adults. Only one
gregarious larval-pupal parasitoid, Oomyzus species (Hymenoptera: Eulophidae) was recorded
from one cocoon of fruit fly, from where sixteen adults emerged comprising of five females and
eleven males. The main disease was powdery mildew which led to the drying of the leaves. The
results demonstrate that that S. edule is attacked by a wide variety of pests. More research is
needed to develop an effective IPM programme and to support adoption of the vegetable to
improve in slums and semi arid areas.
Key words: Sechium edule, insect pests, parasitoids, yield, diseases
142 aGRO 2011 Biennial Conference EFFECT OF VARYING INORGANIC NITROGEN FERTILIZER REGIMES ON
GROWTH, YIELD AND QUALITY OF SNAP BEANS
Kamanu, J. K., Chemining’wa, G. N., Nderitu, J.H. and Ambuko, J.
00625, Nairobi
Abstract (C2019)
Smallholder irrigated farms in central Kenya are characterized by low nutrient levels,
particularly Nitrogen. An on-farm trial was established under furrow irrigation between early
March 2010 and November 2010 at Kimbimbi in Kirinyaga South district to evaluate the effect
of inorganic fertilizer application regimes on growth, yield and quality of snap beans. Fertilizer
treatments comprised: (i) application of DAP at planting and topdressing with CAN at 21 days
after emergence (DAE); (ii) application of DAP at planting and topdressing with NPK-17:17:17
at 21 DAE; (iii) application of DAP at planting, topdressing with CAN at 21 DAE and
topdressing with NPK-17:17:17 at 35 DAE; (iv) application of CAN at planting, topdressing
with CAN at 21 DAE and then topdressing with CAN at 35 DAE; (v) control (no fertilizer
added). The varieties tested were Amy and Serengeti. The trial was laid out in RCBD with a
factorial arrangement and replicated three times. Fresh pod yield was sorted into fine and extra
fine grades. Nitrogen fertilizer regimes delayed seed emergence in the first planting. Serengeti
took a longer time to emerge and flower than Amy. Fertilizer application depressed nodulation.
Generally, application of DAP-CAN and DAP-NPK significantly increased shoot dry weight
while CAN alone had no effect. Serengeti had higher shoot dry matter than Amy. In Amy
variety, only DAP-CAN and DAP-NPK had higher extra fine pods than the control, while all the
fertilizer treatments increased extra fine pods in Serengeti. Serengeti had significantly higher
total extra fine pods than Amy in all treated plots, but not in control plots. All treatments except
DAP-NPK had significantly higher fine pods than the control in Amy while all fertilizer
treatments improved fine pods in Serengeti. DAP-CAN and DAP-NPK fertilizer application had
the most positive effect in Serengeti while DAP-CAN-NPK had the most positive effect in Amy.
Key words: fine pods, extra fine pods, Serengeti, Amy, inorganic fertilizer
143 aGRO 2011 Biennial Conference CONTRIBUTION OF BEE POLLINATION TO SUNFLOWER YIELD AND SEED OIL
CONTENT
*Muo Kasina, Melanie Hagen1, Huria Nderitu2, Manfred Kraemer3, Christopher Martius4
and Dieter Wittmann5
*Kenya Agricultural Research Institute, NARL-Kabete, P.O. Box 14733-00800 Nairobi. 1
Department of Biological Sciences, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C,
Denmark. 2 Mount Kenya University, P.O. Box 342-01000, Thika. 3 Faculty of Biology,
Biological Collection, Bielefeld University, P.O. Box 100131, 33501 Bielefeld, Germany.
4
Centre for Development Research, University of Bonn; Walter-Flex Str. 3, 53113 Bonn.
5
Department of Ecology of Cultural Landscapes -Animal Ecology-, University of Bonn Germany
Abstract (C2021)
Sunflower production in Kenya targets the market offered by cooking oil companies. Prices have
been poor ostensibly because of low seed oil content. This study was done to measure
contribution of bee pollination to sunflower yield and seed oil. Sunflower was grown in a plot of
more than 20 x 20 m in 2005 at Kakamega district of Kenya. At blooming stage, some heads
were left open to allow any pollinator while others were covered with insect proof nets. On the
covered heads, pollinators were allowed to visit and were recorded for about 30 minutes daily
throughout the season. Results show that flowers with unrestricted access by pollinators had
higher yields and seeds were heavier with higher oil content. Generally in all the flowering
heads, female flowers developed first followed by male flowers in a progressive manner from
outwards into the inner core of the head. This prevented forced self-pollination where by pollen
donor and stigma are from same head but different flowers. Honey bees were the most frequent
visitors and best pollinator. Stingless bees were also observed visiting the flowers but were not
efficient as honey bees. Therefore, honey bee pollination has potential of producing quality seed
oil in Kenya. Sunflower farmers are advised to keep or rent honey bees for pollination purposes
to enhance their crop yields and increase cash income. Major sunflower processors could also
promote use of honey bees for pollination to ensure sufficient pollination and increased seed oil
content.
Key words: bees, pollination, seed quality, stingless bees
144 aGRO 2011 Biennial Conference EFFECTS OF BANANA VARIETIES IN CENTRAL AND EASTERN KENYA ON
MACROPROPAGATION TECHNIQUE
Kasyoka Martha R. *, Mwangi M.1, Kori N.2, Mbaka J.2, Gitonga N1.
1
Department of Agricultural Science and Technology, Kenyatta University, P.O. Box 4384400100, Nairobi; 1 Department of Agriculture, Meru University College, P.O Box 972- 60200
Meru; 2 Kenya Agricultural Research Institute, P.O. Box 220 Thika, Kenya.
Abstract (C2022)
Kenyans obtain most of their food, livelihood, employment and foreign exchange from the
agricultural sector. Banana contribution toward this cannot be over looked. Recently banana has
become an important cash crop, especially in Central and Eastern Kenya where income from
traditional crops especially coffee has drastically reduced. However, banana industry is faced by
many challenges among them lack of clean planting materials. Natural regeneration is inadequate
and associated with high risk of pest and disease spread while tissue culture plantlets are priced
above what will be affordable for many small-scale farmers who are the main stake holders.
Macropropagation technology relies on affordable and simple methodology and can be done
easily with adequate training. This has been used in other countries; Cameroon and Nigeria to
increase seedling at farm level. The question is whether this technology can be used to propagate
local banana genotypes. To answer this, macropropagation chambers were set in different
location in Central and Eastern districts namely: Mathioya, Kirinyanga East, Embu East, Meru
Central and Imenti South. Fifteen corms of four different varieties (Kampala, Cavendish, Sweet
banana and kiganda) were initiated in sawdust media in a chamber which humidity and
temperature was increased. Data was collected on earliness of sucker initiation and the number
of suckers (plantlet) of the first 5 corms per variety. In all the six sites, there was a significance
variety difference on the number of days from corm planting to sucker initiation; with Kampala
variety taking shortest time and had more plantlets per corm while Sweet banana took the longest
time and had few plantlets. The response clearly indicated that the 4 varieties can be propagated
through this technology to boost seedlings availability, banana production and food security in
Kenya.
Key words: Natural regeneration, Macropropagation, Seedlings availability, Tissue culture
145 aGRO 2011 Biennial Conference EFFECT OF TEMPORAL WEED COLONIZATION ON THE GROWTH AND
PRODUCTIVITY OF COTTON (Gossypium hirsutum L.) IN CENTRAL KENYA
*Kimunye J. N., Jenesio I.K., Nelson A., Kasina1, M
*School of Biological Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya.
1
Kenya Agricultural Research Institute, Kabete-P.O. Box 14733-00800 Nairobi
Abstract (C2122)
Cotton production in Kenya has been characterized by low yields due to weeds, insect and mites,
and diseases. Uncontrolled weed growth reportedly results to 50–60% yield losses. To determine
effects of temporal weed colonization on cotton, a split plot design was used where the main plot
was weeding (hand weeding and spraying) and subplots were the timing of weeding (3, 6, 9 and
12 weeks after germination (WAG) and no weeding). The plots were maintained weed free after
the treatment application throughout the season. The study was done at Mwea, Central Kenya,
from October 2009 to April 2010. Weeds were sampled using 0.5 x 0.5m quadrats where all
weeds within a quadrat were counted. Cotton height (cm) was measured from soil surface to the
tip while the number of cotton squares and bolls was counted. A total of 43 weed species
mainly from Poaceae and Fabaceae families were recorded. Plots weeded at 3 and 6 WAG were
not significantly different in terms of yields and plant height. They had significantly (P<0.05)
taller plants, more squares and productive bolls compared with those from other treatments.
Plants in these plots were not significantly different (P<0.05) under hand weeding and spraying
regimes (108.14cm±0.687 and 104.39cm±0.950 height 8.19 and 6.43 bolls, and, 8.26 and 6.13
bolls, respectively per plant) though hand weeding showed better effects. There was no
significant different amongst the other treatments. Early weeding up to 6 weeks after germination
is thus recommended to reduce weed colonization and ensure plants establish well with little or
no competition from the weeds.
Key words: Weed infestation, Bolls, yield loss, weed competition
146 aGRO 2011 Biennial Conference EFFECTS OF DIFFERENT HARVEST PERIODS ON POPULATION DYNAMICS OF
POTATO TUBER MOTH (PTM) Phthorimaea operculella (Zeller) ACTIVITY IN FIELD
AND STORE
Koech, A1., Olubayo, F1., Nderitu, J1. , Were, S1., and Kilalo, D1.
Department of Plant Science and Crop Protection, P.O Box 29053- 00625 , Nairobi.
Abstract (C2035)
Potato, Solanum tuberosum L., is the second most important food crop in Kenya after maize and
plays an important role in food security. However farmers face many constraints in its
production, with pests and diseases being the most important. PTM is the most destructive insect
pest capable of causing 25% damage in the field and upto 90% loss in store. The study was
undertaken to determine the effect of different harvest periods; Harvest two weeks before
maturity, Harvest at maturity, Harvest two weeks after maturity and Harvest four weeks after
maturity on PTM activity in the field and later in store. The experiment were set in a complete
randomized design both in the field and in store with four replicates and repeated for two seasons
where larvae, mines and yield were collected as parameters to assess PTM damage. The study
demonstrated that PTM infestation in the store depended much on the initial PTM infestation in
the field. Harvesting two weeks before maturity significantly lowered PTM infestation in the
store (P< 0.001) and population of PTM builds up after two months of storage causing serious
tuber damages. This harvest period also significantly lowered the potato tuber yield (p<0.001).
The results show that harvesting two weeks before maturity has the potential to manage PTM in
storage and can be used by small scale farmers aiming at producing potato seed for their own use
and for sale. Farmers can however accommodate different harvest periods as components of an
IPM strategy for PTM management.
Key words: Management, IPM, PTM, Harvest periods, Seed tubers, Ware potato, Maturity
147 aGRO 2011 Biennial Conference EFFICACY OF LOCALLY AVAILABLE MATERIALS AND BIO-CONTROL AGENTS
IN THE MANAGEMENT OF POTATO TUBER MOTH (PTM) (Phthorimaea
operculella) (Zeller) IN THE STORE
Koech, A1., Olubayo, F1., Nderitu, J1. , Were, S1., and Kilalo, D1.
Department of Plant Science and Crop Protection, P.O Box 29053- 00625, Nairobi.
Abstract (C2036)
Potato (Solanum tuberosum) ranks as the second most important food crop after maize playing
an important role in national food security and income generation in Kenya. Potato production is
limited by pests and diseases with potato tuber moth (PTM) being the most important insect pest
in storage. This study was conducted to evaluate locally available materials and bio-pesticides
for management of PTM. The experiment was conducted for two seasons and was laid out in a
complete randomized design with four replicates. Potato tubers in store were treated with
Carbaryl, Bacillus thuringiensis (Bt), Beauvaria bassiana, rice husks, wood ash, sawdust, sand
and with untreated control. Mines caused by larvae were assessed to estimate PTM damage. The
average PTM Larval reduction varied; Carbaryl 98.5% emerged as the best in controlling PTM
recording the least damage in terms of mines and larval infestation. Bt and rice husks 76% came
second followed by wood ash 50% and saw dust 50% all with significant effect on PTM over
untreated control (p ≤ 0.001). Sand did not have a significant effect on PTM. Bt and rice husks
are effective alternatives to carbaryl in controlling PTM in store. Sawdust, Beauvaria bassiana
and wood ash have the potential to manage PTM in store. These results provide alternatives that
will enable farmers preserve both seed and ware potato.
Key words: Bacillus thuringiensis, Rice husks, Sawdust, Beauvaria bassiana, wood ash, PTM
larvae, Solanum tuberosum.
148 aGRO 2011 Biennial Conference SELECTION OF SEED POTATO VARIETIES FOR ENHANCED FOOD SECURITY IN
KENYA’S NORTH-RIFT REGION
Komen S.K1, J.O Ochudho2 and A.O. Auma.2
1
Kenya Plant Health Inspectorate Service (KEPHIS), P.O. BOX49592-00100, Nairobi. Kenya
2
The Department of Seed, Crops and Horticultural Sciences, Chepkoilel University College, P.O.
BOX 1125-30100, Eldoret, Kenya.
*Corresponding author email: [email protected] OR [email protected]
Abstract (C2121)
Irish potato, (Solanum tuberosum L.) is the World’s fourth and Kenya’s second most important
food crop. Tubers are used as food, economically contribute over 10 billion shillings and create
employment along value market chain. Low productivity is due to diseases, soil infertility and
poor quality seed. Varieties are released without seed production packages necessary in seed
supply. A study to determine the seed size grade of tubers was done at 1600-2900m above sea
level. Six potato varieties were planted at 75cm by 30cm in a Randomised Complete Block
Design in three replications. Fertilizer was applied at 75kg N and 75kg P205 at planting. Weed
and pest control was done using conventional weed control practises. Haulm killing and tuber
lifting were done 75 and 96 days after planting and evaluation for various parameters followed.
Seedling emergence rate and stem density were significant (p=0.05) per location. Seed size
measured as percent tuber yield was highly significant with varieties Kenya karibu, Roslin tana,
Dutch robjn and Asante following each other in order of decreasing seed size. Seed production
should consider variety and altitude since they influence the rate of tuber filling. Haulm killing
should be done earlier in lower than in higher altitudes.
Key words: Selection, Variety, Elevations, Seed sizes, Tuber size distribution
149 aGRO 2011 Biennial Conference EFFICACY OF POCHONIA CHLAMYDOSPORIA AND PAECILOMYCES LILACINUS
AS BIOCONTROL AGENTS OF ROOT-KNOT NEMATODES
Nessie Luambano-Nyoni1,4*, John W Kimenju1, Rama D Narla1, Waceke J Wanjohi2 and
Brian R Kerry3
1
University of Nairobi, P.O. Box 29053-00625, Nairobi, Kenya,
2
Kenyatta University, P.O. Box, 43844 Nairobi, Kenya,
3
Nematode Interactions Unit, Rothamsted Research, Harpenden, Herts. AL5 2JQ, UK,
4
Sugarcane Research Institute, P.O. Box 30031, Kibaha, Tanzania
Abstract (C2113)
Management of root-knot nematodes (Meloidogyne spp.) using fungi that parasitize eggs and
females has been gaining popularity as alternatives or supplements to chemical nematicides.
This study was conducted with the aim of screening isolates of Pochonia chlamydosporia and
Paecilomyces lilacinus in managing root-knot nematodes. Efficacy of six isolates (10, 126, 144,
147, 177 and 392) of P. chlamydosporia and two isolates (Pl-Rothamsted and Pl-plus™) of P.
lilacinus was assessed in laboratory and greenhouse using tomato as a test crop. Isolates 10 and
392 were significantly (P<0.001) more effective in parasitizing nematode eggs compared to
other isolates. A significant (P<0.001) reduction, of up to 88%, in the numbers of second-stage
juveniles compared to the untreated control was achieved with Pl-plus in sterilized and nonsterilized soil and with isolate 10 in non-sterilized soil. Shoot weight was 95% and 69 % higher
in plants treated with isolates 392 and 10 respectively, compared to the control in non-sterilized.
Therefore, isolates 10 and 392 were most effective at controlling root-knot nematodes compared
to the other fungal isolates. It can therefore be concluded that Pochonia chlamydosporia and
Paecilomyces lilacinus have the potential that can be exploited in the management of the plant
parasitic nematodes.
Key words: Pochonia chlamydosporia, Paecilomyces lilacinus, root knot nematode, biological
control
150 aGRO 2011 Biennial Conference RESPONSE OF SWEETPOTATO DUAL PURPOSE VARIETIES TO HARVESTING
REGIME
Manoa Lonita1, Charles Gachuiri1, Ben Lukuyu2, Jane Wamatu1, Sammy Agili3, Joyce
Maina1
1
University of Nairobi, Department of Animal Production, Kenya
2
International Livestock Research Institute (ILRI), Kenya
3
International Potato Center (CIP)
Abstract
(A2044)
Feeds are a major constraint to livestock production in Kenya. Sweetpotato dual purpose
varieties can be used to reduce feed resource competition and provide high quality livestock
feeds during dry seasons. A study was done to evaluate the dry matter yields of six sweet potato
varieties. Specific objectives were to determine dry matter yield of vines and tubers, root to vine
ratios, marketable roots, and performance of the six varieties at different harvesting regimes (75
and 150 days post planting).The varieties tested were Gweri, Kemb-23, Naspot-1, Musinyamu,
Wagabolige and 103001.152. The research was conducted at the Kabete Campus Field Station,
University of Nairobi and was laid out in a split plot randomised block design replicated three
times. Varieties constituted the main plots while the numbers of days to harvest were the subplots. Dry matter vine yield of Musinyamu variety (3.9 tDM/ha) was higher (P<0.05) than
103001.152 (1.3 tDM/ha). Tuber yield of Naspot-1 was higher (P<0.05) (5.1 tDM/ha) than
Gweri (1.2 tDM/ha); 103001.152 had higher root to vine ratio (3.0) than Gweri (0.3), while
Naspot-1 produced more marketable roots (P<0.05) than Gweri. Dry matter yields of vines and
tubers root to vine ratios and marketable roots increased as the number of days to harvest
increased. Dry matter yields of both vines and tubers increased with age due to reduction in
moisture content and increased cell wall contents. Harvesting vines at 75 days negatively
affected root production at 150 days, showing that frequent defoliation of sweet potato plants
disrupted the photosynthetic process reducing root production. The R/V ratios obtained classified
Gweri (0.3), Kemb-23 (0.8), Wagabolige (0.7) and Musinyamu (0.6) as forage varieties,
103001.152 (3.0) as low root production and Naspot-1 (1.7) as high dual purpose variety. The
study shows that sweet potatoes can be used both as livestock feeds and food for humans.
Keywords: Harvesting regime, Marketable roots, Sweetpotato, Vine: root ratio, Dual-purpose,
Dry matter
151 aGRO 2011 Biennial Conference ESTABLISHMENT OF IN VITRO POTATO (Solanum tuberosum L.) GERMPLASM
COLLECTION IN KENYA
Mbiyu Miriam *, Charles Lung’aho1, Patrick Pwaipwai, Christine Muchira, Jane Muthoni,
Joseph Ngaruiya and Susan Otieno
1
Kenya Agricultural Research Institute (KARI)-Tigoni, P.O Box 338 Limuru 00217, Kenya
*Kenya Agricultural Research Institute (KARI). National Potato Research Centre, Tigoni.
Corresponding Email: [email protected]
Abstract (C2046)
Limited supplies of disease free nuclear seed stocks for further multiplication is a serious
obstacle to further development of the potato industry in Kenya. A nucleus set of disease free
and true to type cultivars must therefore be conserved to ensure regular supply of disease free
planting material to the industry. The objective of this study was to establish an in vitro
germplasm collection of potato using slow growth in vitro techniques. The conservation media
consisted of Murashige & Skoog salts with normal vitamins, 8g/l agar and supplemented with
40g/l mannitol, 40g/l sorbital with and without GA3, incubated at 20 ± 20C under a 16 h
photoperiod with 3,000 lux. 10 potato accessions were assessed on the survival rate of meristem
and slow growth media. The results showed that 60-70 % of the meristems per genotype
survived to form plantlets. Mannitol and sorbital at 40g/l with 0.001GA3 provided the best
survival rate of 80-90% after 14 months of conservation with high regeneration rates.
Conservation media consisting of mannitol and sorbital at 40g/l but without GA3 had a survival
rate of 55-60% after 14 months of conservation with high regeneration rates. Slow growth in
vitro conservation procedures offered several advantages including: easy availability of cultivars
for micropropagation; permitting virus eradication through meristem culture; and avoidance of
exposure of germplasm to environmental disturbances such as drought. Investigations of
alternative sources of gelling agents and carbon sources should be done to further reduce costs of
conservation.
Key words: in-vitro conservation, disease free nuclear seed stocks, potato
152 aGRO 2011 Biennial Conference ASSESSMENT OF COMMON BEAN (Phaseolus vulgaris L.) YIELD AND WATER USE
EFFICIENCY IN RESPONSE TO NITROGEN FERTILIZER UNDER SEMI-ARID
ENVIRONMENT
Mburu D. M.
Jomo Kenyatta University of Agriculture and Technology (JKUAT), Department of Land
Resources Planning and Management. P.O. Box 62000- 00200, Nairobi
Corresponding Email: [email protected]
Abstract (C2115)
Common bean (Phaseolus vulgaris L.) is an important food crop in the semi-arid areas of Kenya
but its productivity is limited by low soil fertility. Although beans obtain nitrogen derived from
atmospheric fixation, they still require external supply of nitrogen at the early stage of
establishment for maximum production. Assessment of three bean varieties (GLP 585, GLP 1004
and Pinto) was carried out at Longonot for two years between 2003 and 2004 to evaluate the
crop yield and water use efficiency in response to nitrogen fertilizer application. The
experimental design was a randomized complete block laid out as split plot and replicated three
times. Phosphorus was applied as basal fertilizer in form of triple superphosphate at planting at
the rate of 18 kg P/ha. Nitrogen was applied in form of Urea at the rate of 0 and 18 kg N/ha.
Nitrogen was applied in two equal splits at 20 and 40 days after crop emergence. Fertilizer
application was main plots while bean varieties were sub-plots. There was no significant
difference in bean yield amongst the varieties, but there was significant difference in yield
between seasons. There was no significant yield response to nitrogen fertilizer in all the seasons
due to inadequate rainfall that was poorly distributed. Water use efficiency was influenced by
rainfall distribution within the growing season. The bean crop was harvested in three out of four
seasons.
Key words: Bean yield, nitrogen fertilizer, semi-arid Kenya
153 aGRO 2011 Biennial Conference WATER AND LIGHT USE IN MAIZE INTERCROPPED WITH MUCUNA
*1
1
MWK Mburu, 2JG Mureithi and 1CKK Gachene
Faculty of Agriculture, University of Nairobi, P .O. Box 29053 – 006250 Nairobi, Kenya
2
Kenya Agricultural Research Institute, National Agricultural Research Laboratories. P. O Box
14733, Nairobi. Kenya
* Corresponding author: Email: [email protected]
Abstract (C2049)
High biomass yielding legume Mucuna pruriens L (mucuna) can improve soil nutrient status in
low input maize production systems if integrated as a cover crop. The amount of mucuna
biomass would be influenced by water and light use in the systems. Field experiments were
conducted at the University of Nairobi Kabete Field Station for three seasons to investigate the
effects of mucuna planting density and planting time on light and water use of maize-mucuna
intercrop. Maize was inter-planted with mucuna at two mucuna planting densities and three
planting times. Mucuna planting densities of 44,000 and 88,000 plants ha-1 were obtained by
planting one and two rows of mucuna between maize, respectively. The planting times were 0, 2
and 4 weeks after planting maize. The experiment design was randomized complete block
replicated three times. Canopy photosynthetically active radiation (PAR) interception, soil water
content, mucuna and maize biomass and maize grain yield were measured. Sole mucuna, maizemucuna intercrop, sole maize and mucuna under maize intercepted 90%, 80%, 65% and 30%,
respectively of PAR. Soil water content was comparable among the treatments. Maize grain
yield was comparable in sole and intercrop but mucuna biomass in the intercrop was reduced by
26-56%. Land equivalent ratio was 0.96. Planting density did not influence mucuna biomass but
delayed planting reduced biomass at 10% per week. The amount of mucuna biomass produced in
the intercrop can improve maize production. Planting mucuna at the same time as maize is the
best option in an intercrop system. Maize-mucuna rotation would be a better option where land is
not limiting.
KEY WORDS: Ceptometer, neutron probe, root length density
154 aGRO 2011 Biennial Conference EVALUATION OF RESISTANCE OF SNAP BEAN VARIETIES TO BEAN FLY
Misheck, D. K.1,*, Nderitu, J.H.1, Kasina, J.M.2, Ndiema, G. C.1 , Olubayo, F.1,
1
Department of Plant Science and Crop Protection, University of Nairobi. P.O. Box 2905300625, Kangemi, Nairobi, Kenya. Tel 020-2055129
2
Entomology & Biotechnology, Kenya Agricultural Research Institute, NARL-Kabete, P.O. Box
14733-00800 Nairobi, Kenya.
*
Corresponding author [email protected]
Abstract (C2050)
Snap bean (Phaseolus vulgaris), an important export crop for Kenya, experiences high pest
infestations leading farmers to use highly persistent pesticides resulting in produce rejection due
to high pesticide residues. A study was carried out to evaluate varietal resistance of seven
commercial snap bean varieties to bean fly. The studies were conducted over three cropping
cycles at Mwea from Feb 2010 to Jan 2011. Each of the seven snap bean varieties (Amy,
Alexandra, Bravo, Serengeti, Paulista, Tana and Mara) was grown with and without Confidor
(imidacloprid (N-[1-[(6-Chloro-3-pyridyl) methyl]-4,5-dihydroimidazol-2-yl]nitramide). The
chemical was sprayed on the soil surface three days after emergence and on the foliage ten days
later. Data was collected weekly throughout the growing period on plant stand, number of bean
fly ovipuncture marks, number of bean fly maggots and pupae and pod yield. The varieties were
significantly different in the number of plants (P=0.001), marketable (P=0.001) and total pod
yields (P=0.001). Alexandra and Serengeti had higher plant numbers and yields than the other
varieties. Treatment of varieties with Confidor increased pod yield in all the varieties by between
50 and 490% but only some degree of resistance was noticed in Alexandra and Serengeti against
bean fly which was enhanced by treatment with Confidor. Therefore, for effective protection
against bean fly, Confidor, which is a relatively safe pesticide, should be integrated with resistant
varieties in snap bean production system. These two bean fly-resistant varieties could be
recommended to snap bean farmers in areas like Mwea which experience high infestation of snap
bean pests.
Key words: imidacloprid, Ophiomyia spp., Phaseolus vulgaris, varietal resistance,
155 aGRO 2011 Biennial Conference LIFE CYCLE, POPULATION BUILDUP AND SURVIVAL OF APHIDS ON STORED
POTATO TUBERS
Munyua L.1, F. Olubayo2 and E. Obutho2
1
Kenya Plant Health Inspectorate Service (KEPHIS), P.O. Box 49592-00100, Nairobi. Kenya.
2
University of Nairobi, Faculty of Agriculture, Department of Plant Science and Crop
Protection, P.O Box 29053 - 00625, Nairobi, Kenya.
Abstract (C2124)
Monitoring of aphid life cycle and population buildup on stored potato tubers aims at
contributing towards development of a viable and sustainable aphid and virus management
strategy. Potato storage protects potatoes from undesirably high air temperatures and
correspondingly low relative humidity and reduces opportunities for pests to aggrevate losses.
Duration of storage and aphid infestation of potato seed are positively correlated. Certified
sprouted Asante and Tigoni variety tubers were used between January and May 2005 to assess
life cycle, population buildup and survival of aphids under storage conditions. Treatments were
replicated three times with newly borne 2nd instar Macrosiphum euphorbiae being introduced
onto three hundred sprouted tubers per treatment arranged in Completely Randomised Design
(rephrase sentence on design and treatments, if possible). Aphid counts were done for thirty days
per treatment with moulting period and the birth rate recorded. Morphological changes, colour,
size, length of nymphal cycle was recorded as were temperature and relative humidity.
Macrosiphum euphorbiae had four different life stages and each life stage showed two
significant distinct peaks per variety. Macrosiphum euphorbiae life cycle was nine and seven
days on Asante and Tigoni varieties, respectively and survived on sprouted tubers as new
generations developed. Macrosiphum euphorbiae a vector of Potato leaf roll virus multiplies and
thrives well on stored potato tubers under temperatures of 18oC to 25oC and high relative
humidity of 75% to 90% and low relative humidity of 44% to 55%. Stringent aphid and virus
management measures should target reduced seed degeneration since aphid vectors can infect
stored sprouted tubers. Expensive results of several years of seed multiplication are rapidly lost if
no attention is directed to aphid transmission of severe viruses during storage. Adoption of semidiffused light stores technology could lead to reduced seed degeneration due to virus infection.
Key words: Asante, Tigoni, Potato varieties, temperature, relative humidity
156 aGRO 2011 Biennial Conference PREDISPOSING FACTORS TO AFLATOXIN CONTAMINATION OF MAIZE IN
EASTERN KENYA
1
Mureithi*, B. K., 2Muthomi, J. W., 2Chemining’wa, G. N. and 2Mutitu, E. W
1
Ministry of Agriculture, P.O. Box 30028, Nairobi, Kenya.
2
Department of Plant Science and Crop Protection, Faculty of Agriculture, University of
Nairobi, P. O. Box 30197, Nairobi, Kenya
Abstract (C2055)
Maize is the staple diet of majority of Kenyan population but repeated outbreaks of mycotoxin
poisoning in Eastern Kenya is a major food safety constraint. This study was conducted to
determine maize production and handling practices that contribute to aflatoxin contamination in
maize in Eastern Kenya. A survey was conducted in Makueni, Machakos, and Kitui districts of
Eastern province during 2008 and 2009 cropping seasons. Information gathered included
agronomic practices, harvesting, drying, storage materials and structures used, transportation,
processing and weather conditions during harvesting and storage. Such practices included
planting of uncertified seeds, harvesting maize before safe moisture content, drying grain on bare
ground, storage in living houses and use of synthetic or polythene bags. Aflatoxin B1 was
detected in maize and maize products at levels above the national legal limit of 10µg/kg. Some of
the maize production and handling practices in Eastern Kenya such as unfavourable drying and
storage practices, planting uncertified seeds, harvesting maize with high moisture content and
storage in living houses may predispose maize to fungal and mycotoxin contamination. In
addition, high temperatures and periodic drought contribute to the higher fungal and aflatoxin
contamination. Therefore, there is need for continued mycotoxin awareness campaigns to
educate farmers, traders, transporters and processors on proper handling practices during
harvesting, drying, storage and transportation of maize to avoid contamination with aflatoxin.
Key words: Aflatoxin, eastern Kenya, handling, maize, mycotoxins, production
157 aGRO 2011 Biennial Conference EFFECTS OF SILVER THIOSULPHATE PRETREATMENTS ON HARVESTED
LISIANTHUS (Eustoma grandiflorum) CUT FLOWERS
Musembi1, Nicodemus Ndawa; Winnie Wanjiku Murigi1 and Margaret Jesang
Hutchinson1
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 2905300625, Nairobi, Kenya.
Abstract (C2057)
This study aimed at developing postharvest pretreatments for improving vase life and display
quality of lisianthus cut flowers. Equally spaced doses (0, 0.25, 0.5, and 0.75 mM Ag+) of silver
thiosulphate (STS) pretreatments were applied for equally spaced durations of exposure (0, 2, 4
and 6 h) to harvested lisianthus cut flowers. STS pretreatment was followed by vase solutions
containing 2% sucrose and 1.5% sodium hypochlorite (Jik®). Pretreatment with 0.75 mM Ag+ for
duration of 2 or 6 h improved vase life by 55% and 40%, compared to distilled water control and
the placebo, respectively. The interaction effect of STS dose and duration of exposure
significantly influenced water uptake, transpiration, and water balance rates. Vase-life
constituted of duration to 50%: wilted florets, or bent-necks, or chlorotic leaves; whichever came
first. Out of the above recommended dosages and duration of exposure, 2 h was found less
reliable than 6 hrs. The duration of exposure of 4 h was found to be detrimental for STS doses
above 0.25 mM Ag+. The significant efficacy of STS at low doses and duration of exposure
revealed in this study presents an immediate solution towards the gradual phase-out of STS
which is a potent environmental pollutant due to the silver content. Further research is
recommended to identify alternatives to STS.
Keyword: Lisianthus, Eustoma grandiflorum, Postharvest technology, Silver thiosulphate,
Heavy-metal environmental pollutant, Water relations.
158 aGRO 2011 Biennial Conference THE EFFECT OF MODIFIED ATMOSPHERE PACKAGING ON POSTHARVEST
SHELF LIFE OF MANGO FRUITS, Mangifera indica L, CULTIVAR TOMMY ATKINS
Mutinda Jackline1, Ambuko, J1. and Owino, W2
1
Department of Plant Science and Crop Protection, University of Nairobi.
2
Agriculture and Technology
Abstract (C2060)
Modified atmosphere packaging (MAP) is a simple technology whose optimization can
minimize high postharvest losses in perishable commodities. In this study, the efficacy of active
bag® a recently introduced MAP product in Kenya in prolonging the postharvest shelf of mango
fruits, cultivar Tommy Atkins was evaluated. Mango fruits harvested at commercial maturity
stage were selected for uniformity and randomly separated into five batches. The five
experimental treatments included three different active bags of varying permeability (A35, A45
and A75), the ordinary polythene bag used commercially and unpackaged control. A random
sample of five fruits was taken every three days from each of the treatments and evaluated for
ripening related physiological changes including respiration, ethylene evolution, cumulative
weight loss, changes in hue angle, firmness and 0brix. All the MAP treatments significantly
enhanced postharvest longevity of the fruits compared to the unpackaged fruits. Active bag
packaging gave better response compared to the ordinary bag, with active bag A35 showing the
best response for all the parameters measured. Fruits packaged in active bag A35 retained
firmness (five fold) and hue angle (60%), while cumulative weight loss was reduced almost three
fold relative to the unpackaged control. Additionally, ethylene evolution and respiration rates
were significantly suppressed by all the active bag treatments. Higher 0brix levels in unpackaged
fruits were indicative of faster ripening compared to MAP treated fruits. These findings show
that active bag can potentially prolong the postharvest shelf life and extend the marketing period
of mango fruits, thereby reducing postharvest losses. For commercial application of active bag
products, more research on their effect on other fruit quality attributes is recommended.
Key Words: Mango, postharvest, shelf life, quality, MAP
159 aGRO 2011 Biennial Conference EVALUATION OF SWEETPOTATO VARIETIES FOR RESISTANCE TO SWEET
POTATO VIRUS DISEASE AND ADAPTABILITY
*1Muturi P. W., M.W.K. Mburu1, J.K. Mwololo 2, E. M. Ateka3, R.W. Njeru 1 and K.
Njoroge 1
1
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 2905300625, Nairobi, Kenya.
2
Pwani University College, P.O. Box 195, 80108 Kilifi, Kenya
3
Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, P.O
Box 62000, Nairobi
Abstract (C2062)
Sweetpotato virus disease (SPVD) is caused by dual infection of the aphid-borne sweetpotato
feathery mottle virus (SPFMV) and the whitefly-borne sweetpotato chlorotic stunt virus
(SPCSV) and it greatly reduces tuber yield. Farmers grow varieties that are susceptible to SPVD
because they do not know whether resistant materials to the disease are available. A cheap way
to control the disease would be to evaluate a diverse range of sweetpotato varieties and identify
SPVD tolerant ones. The objectives of this study were to identify sources of resistance to SPVD
and evaluate the materials for adaptability in these areas. Twenty sweet potato cultivars
comprising of improved varieties and local landraces were established in the field at Kabete, Juja
and Kibirigwi in Kenya during the long and short rain seasons in 2006. Seedlings were
challenged with natural SPVD infection by planting two rows of sweet potato spreader plants in
around each plot. The trial was laid out as a randomised complete block design replicated three
times. Results showed that varieties differed significantly (P<0.01) in response to SPVD.
Zapallo, Jonathan and Japonese were tolerant while Jewel, Mugande and 440015 were
susceptible to SPVD. Tolerant varieties were stable across environments in relation to SPVD
thus could be cultivated by farmers in areas where SPVD prevalence is high. These results show
that possibly variety Japonese, Jonathan and Zapallo possess good levels of tolerance, and could
be used to improve the level of tolerance of the land races. Tolerant and moderately susceptible
varieties were stable among environments in relation to disease incidence. There is need to
investigate the inheritance of this resistance in sweet potato.
Key words: Sweet potato, plant resistant, SPFMV, SPCSV, Yield
160 aGRO 2011 Biennial Conference DECOMPOSITION AND NUTRIENT RELEASE RATES OF SELECTED LEGUME
RESIDUES IN A COLD SEMIARID ENVIRONMENT OF LAIKIPIA COUNTY
Mwangi P.W. 1; G.N.Chemining’wa2; M.W.K.Mburu2 and J.G. Mureithi1
1
Kenya Agricultural Research Institute
2
University of Nairobi, Department of Plant Science and Crop Protection
Abstract (L1025)
Incorporation of legume residues in soil is a low cost option for improving soil fertility, but its
effectiveness depends on residue quality. A study was conducted for two seasons (2007 and
2008) to determine the decomposition and nutrient release rates of butter bean, grasspea,
common bean and chickpea residues. Chopped legume residues were placed in 2 mm nylon
mesh bags and incubated in the soil at a depth of 15 cm. Dry matter weights and composition
(cellulose, lignin, C, N, P, K, Mg and Ca) of residues were determined before incubation and
thereafter fortnightly until the 14th week after incubation. Chickpea residues had significantly
higher initial % lignin and lignin/nitrogen ratio than butter bean, grasspea and common bean
residues. All residues had similar levels of cellulose, C/N ratio, N, C, P, K, and Ca. Nitrogen
concentrations were above the critical values (18-22 g/kg) for net N mineralization in all the
legumes whereas P concentrations were below the critical value (2.5 g/kg) for net P
mineralization in chickpea and common bean. Dry matter and nutrient (N, P, K, Mg and Ca)
disappearance rates of chickpea residues were significantly lower than for grasspea, butter bean
and common bean. Grasspea residues had higher dry matter disappearance rates than other
legumes’ residues. Grasspea and butter bean residues had significantly higher nutrient
disappearance rates than common bean residues. Nutrient loss from all the residues was in the
order K > P > N > Mg > Ca. Butter bean and grasspea crop residues have potential of
providing soil N, P, K and Mg in the cold semi-arid region within a growing season.
Key words: composition, decomposition, nutrients, residues, legumes, dry matter
161 aGRO 2011 Biennial Conference MORPHOLOGICAL DIFFERENCES AMONG SUSCEPTIBLE AND RESISTANT
SWEETPOTATO VARIETIES
Mwololo JK3*, Mburu MWK1, PW Muturi PW1, Njeru RW1, Njoroge Kiarie1, Ateka EM2,
and Munyua JK 1
1
Department of Plant Science and Crop protection, University of Nairobi, P.O Box 29053
Nairobi. 2Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology,
P.O Box 62000 Nairobi. 3*Pwani University College, P. O. Box 195, 80108 Kilifi, Kenya.
Abstract (C2064)
Physical, chemical and physiological properties of the plant leaves and stems play an important
protective role against pathogens. Morphological, anatomical and serological studies were
conducted on sweet potato varieties to determine the role of the traits in relation to sweet potato
response to viral diseases incidence described, especially the sweet potato virus disease (SPVD).
The morphological characteristics included petiole and internode length and pubescence.
Anatomical attributes of nine sweet potato varieties were studied using light microscopy.
Serological tests were conducted on sweet potato leaves with nitrocellulose membranes enzymelinked immunosorbent assays (NCM-ELISA) to test for presence of viruses that commonly infect
sweet potato in Kenya. There were significant differences (P <0.05) among the sweetpotato
varieties for the triats measured. The sweet potato varieties which were tolerant SPVD had
longer internodes and petioles, thicker leaf and stem cuticles and low hair density on leaves and
stems compared to the susceptible varieties. The sweetpotato virus titres were high in the most
susceptible varieties (Jewel, Mugande) compared to the resistant (Jonathan, Zapallo) out of the
samples tested. The sweetpotato mild mottle virus (SPMMV), sweetpotato chlorotic stunt virus
(SPCSV), sweetpotato feathery mottle virus (SPFMV) and the sweetpotato chlorotic stunt virus
(SPCFV) were on average 22%, 36%, 32% and 11%, respectively among the 20 varieties. Sweet
potato morphology can form a basis for rapid assessment of SPVD tolerance among varieties.
The multiple infections involved SPCSV and this was common in most of the diseased plants
hence the importance of targeting resistance to SPCSV through crop improvement programs.
Key words: Cuticle, hairiness, Host plant resistance, sweetpotato virus disease
162 aGRO 2011 Biennial Conference QUALITY AND YIELD OF SNAP BEAN LINES DEVELOPED FOR MULTIPLE
DISEASE RESISTANCE
Wahome S.W., P.M. Kimani, J.W. Muthomi and R.D. Narla
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 29053-00625
Nairobi, Kenya
Abstract (C2101)
Angular leaf spot, anthracnose and rust are a major constraint to snap bean (Phaseolus vulgaris)
production and development of varieties with multiple disease resistance would assist farmers
reduce reliance on fungicide and therefore, meet the stringent European export requirements. The
objective of this study was to select snap bean populations and lines with high pod quality and
yield. Forty five advanced bush snap bean lines and six climbing snap lines were evaluated at
KARI-Thika and Mwea for two seasons. The materials included populations with resistance to
rust, anthracnose, angular leaf spot and rust and susceptible popular varieties with good pod
quality. The populations were advanced to F4, F5 and F6 and experiment laid out as split-plot,
with fungicide treatments as main plots, and genotypes as sub-plots. Days to flowering and
maturity, pod length and width, number of pods per plant, marketable pod yield, pod quality and
seed yield were determined. There were significant differences (P≤0.05) among the genotypes in
marketable pod yield, pod quality and seed yield. HAB 428 had the highest pod yield of 8528.2
kg ha-1 when the genotypes were grown without application of fungicides. A total of 674 single
plants with desirable pod characteristics were selected. Snap bean line KSB 10 BR with multiple
disease resistance had the highest extra fine pod yield of 2000 kg ha-1. All climbing lines had
thicker pods compared to bush lines. Some of the advanced lines selected for multiple diseases
resistance could not meet the yield and quality of bush commercial varieties. The study showed
that some of the snap bean lines and populations evaluated could be useful in development of
snap bean varieties with multiple disease resistance and high yields of acceptable quality.
Key words: Snap beans, multiple disease resistance, pod quality, pod yield
163 aGRO 2011 Biennial Conference TRANSFERRING STRIGA RESISTANCE GENES INTO FARMER PREFERRED
SORGHUM VARIETY IN RWANDA
Niyibigira Theogene1, Kahiu Ngugi2, Eunice Mutitu3, Dan Kiambi4, Santie DeVilliers 5
1,2,3
University of Nairobi, Plant Science and Crop Protection department, Kenya
4
African Biodiversity Conservation and Innovations Center (ABCIC)
5
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)
Abstract (C2119)
Striga hermonthica is one of the major constraints of sorghum production world-wide and
particularly in eastern province of Rwanda. In this study, 5 Striga resistance Quantitative Trait
Loci (QTLs) from a resistance donor N13 line and located on SBI-01, SBI-02, SBI-05 (with 2
QTLs) and SBI-06 were transferred into IS8193 line, a farmer preferred sorghum variety in the
eastern province of the country. The transfer was performed using Simple Sequences Repeats
(SSRs) molecular markers. Nine foreground polymorphic SSR markers were used to identify F1
progenies carrying Striga resistance QTLs. From a cross between IS8193 and N13, a total
amount of 20 F1 progenies were genotyped and 16 of them were found to have one to three
introgressed Striga resistance QTLs. The 16 selected genotypes were backcrossed to IS8193 to
produce BC1F1 generation. After BC1F1 progenies genotyping, 12 BC1F1 lines were identified
to carry one to three Striga resistance QTLs and were again backcrossed to IS8193 to produce
BC2F1 genotypes. The BC2F1 generation with one to three QTL will be genotyped to produce
BC3F1 and also selfed to BC2S1 to produce almost stable Striga resistant sorghum lines for
adoption by farmers in Rwanda.
Keywords: Sorghum, Striga hermonthica, molecular markers, SSR markers
164 aGRO 2011 Biennial Conference MACROPROPAGATION TECHNOLOGY TO PRODUCE BANANA SEEDLINGS
FREE FROM PLANT PARASITIC NEMATODES IN CENTRAL AND EASTERN
KENYA
Njeri Njau1*, Maina Mwangi1, Ruth Gathu1, Jesca Mbaka2, Reuben Muasya1
1
Department of Agricultural Science and Technology, Kenyatta University, P.O. Box 4384400100, Nairobi; 2 Kenya Agricultural research institute, P.O. Box 220 Thika, Kenya.
Abstract (C2126)
Banana (Musa spp) is one of the most important food crops contributing to food security for
majority small holders in Kenya. However, banana production has not reached its full potential
due to pest infestation. Plant parasitic nematodes (PPN) are major pests of banana mostly
transmitted to new fields through infested planting material. Macropropagation is a technology
that can produce affordable seedlings. A survey was carried out in Eastern and Central regions in
Kenya to determine important banana pests and diseases. PPN was found in more than 20% of
the farms surveyed. These were Radopholus spp. and Pratylenchus spp. Macropropagation
nurseries were set up in Meru Central, Imenti South Mitunguu, Imenti south Tharene, Kerugoya,
Embu and Mathioya districts and in Kenyatta University to evaluate the efficiency of
Macropropagation technology to produce banana seedlings free from PPN. Selection of corms
was done using an established protocol. Five functional roots were selected randomly from 10
corms of each variety used for propagation and scored for nematode damage. Seedlings that
arose from the nurseries were monitored and tested for presence of PPN. Results showed that
92% farmers in the area surveyed use suckers as the major propagating material thus increasing
the chances of disseminating the pest. Furthermore, less than 15% of the farmers treat their
suckers prior to planting. The roots scored showed that Kampala, Sweet banana, Uganda green
and Cavendish banana varieties had 19%, 23%, 36% and 46% damage respectively, indicating
more damage in Cavendish varieties which are used for commercial purposes. 100% of the
seedlings showed no symptoms of infestation. No PPN were extracted from any of the roots.
Macropropagation technique can be used to produce banana seedlings that are free of plant
parasitic nematodes. This technology should be taught to farmers to improve banana productivity
and the life of plantations.
Key words: Musa spp, Macropropagation, Plant Parasitic Nematodes, banana varieties
165 aGRO 2011 Biennial Conference CHEMICAL CHARACTERIZATION OF TEN DUAL PURPOSE SORGHUM
VARIETIES FOR ANIMAL FEED IN ARID AND SEMI-ARID AREAS OF KENYA.
Njiru, A.N.1, B.N. Mitaru2 and M.N. Badamana2
1
Ministry of Livestock Development, P.O. Box 1188 Machakos,
2
Department of Animal Production, University of Nairobi, P.O. Box 29053-00625 Nairobi
*Corresponding author: [email protected] or [email protected]
Abstract (A2071)
A study was designed to evaluate ten dual purpose sorghum varieties (NGUUGU, MACIA,
BTX623, IESV91131DL, IESV92089DL, IESV92165DL, IESV99006 DL, IESV99026DL,
IESV99095DL and SDSL90162-2) for nutritional performance with view to recommend the best
suited for animal feed in arid and semi-arid areas. The trial was conducted at KARI Kiboko,
Machang’a and Kambi ya Mawe. The categorization into dual purpose was based mostly on
biomass yield, grain yield and overall agronomic expression. At the age of 14 weeks, destructive
sampling was conducted to obtain samples for chemical composition evaluation. The samples
were separated into panicles, leaves, stems and whole plant. They were analyzed for DM, CP,
NDF, ADF, ADL and Hemicellulose. DM content of the ten sorghum varieties ranged from 91.2
to 92.57%, while CP was in the range of 5.13 - 6.61%. The NDF was highest (P≤0.05) in
Nguugu (73.79%) and lowest in IESV99006 DL (58.52%). The ADF content followed the same
pattern with Nguugu showing the highest (P≤0.05) value (34.23%) and IESV99006 DL with the
lowest value (23.94%). The hemicellulose and ADL contents were similar with values of 33.85 39.56% and 4.55 - 5.8%, respectively. Plant parts, the leaves had higher (P≤0.05) DM content
(92.34%) than panicles (91.71%) and stems (91.28%). The panicle showed the highest (P≤0.05)
CP content (7.07%) while stem had lowest value (3.92%). The NDF values obtained were
highest (P≤0.05) for stems (70.68%) and lowest in panicles (60.25%). The ADF, Hemicellulose
and ADL showed higher (P≤0.05) values in leaves and stems and lower values in panicles. A
combination of ability to produce relatively higher dry matter digestibility, crude protein and low
fibre constituents, in addition to biomass yield leads to ranking variety IESV99006DL and
IESV92165DL as top for dual purpose production.
Key words: Nutritional evaluation, Plant parts, sorghum, varieties, Kenya
166 aGRO 2011 Biennial Conference TRIVIA WP: AN ALTERNATIVE TO METALAXYL FOR POTATO BLIGHT
CONTROL IN KENYA
1
Nyongesa, M.W., 1Lung’aho, C. and 2Ngatia, T.
1
KARI National Potato Research Centre-Tigoni P.O. 338-00217 Limuru.
2
Bayer East Africa Ltd. P.O. Box 30321-00100 NAIROBI.
Abstract (C2074)
Late blight (Phytophthora infestans) is a major constraint to potato production in Kenya. A field
study was carried out to determine the efficacy of Trivia 727 WP - a non-phenylamide fungicide
in the control of foliar blight on a susceptible potato cultivar. Trivia 727 WP at 1.2Kg/ha and
1.75Kg/ha was evaluated alongside Ridomil Gold 68 WP at 2.5 Kg/ha on a schedule of 7, 10 and
14 day intervals and an unsprayed control during the 2008 long and short rains seasons. Treated
plots laid out in a split-plot design were assessed for disease severity from the time disease
symptoms were observed in the control plots and subsequently at 7-day intervals until crop
maturity when plots were assessed for tuber yield at harvesting. Trivia 727 at 1.75 Kg/ha had
significantly lower mean area under disease progress curve than the untreated control and
resulted in a significant increase in tuber yields (p<0.05). Application of Trivia 727 at 7 or 10
day intervals resulted in higher tuber yield increases than application of Ridomil Gold at similar
intervals. However, application of Ridomil Gold at 14 day intervals resulted in higher tuber yield
increases than Trivia 727 WP applied at similar intervals. We conclude that Trivia 727 WP
imposes blight control comparable to that achieved from use of Ridomil Gold at similar rates and
application intervals. Based on our findings, we recommend the use of Trivia 727 WP in
optimized spray programs to reduce the risk of selection for fungicide resistant strains of potato
blight in Kenya.
Key words: late blight, phenylamide, Phytophthora infestans
167 aGRO 2011 Biennial Conference THE EFFECTIVENESS OF COCCINELLIDS AS NATURAL ENEMIES OF APHIDS IN
MAIZE, BEANS AND COWPEAS INTERCROP
1
Nyukuri W.Robert 1khaemba M.Battan 1Wanjala M.Fred 2Odhiambo O.Jared and
3
Cheramgoi Evelyne
1
Department of Biological Sciences, School of Science, Moi University. 2Department of Physics,
School of Science, Masinde Muliro University. 3Department of Plant Protection, Tea Research
Foundation
Corresponding author: [email protected].
Abstract (C2065)
A field study was conducted in Busia district of Kenya to elucidate the dynamics of ladybirds in
mixed stands of maize, beans and cowpeas to determine their efficacy as sole control measures
for aphids. Maize, beans and cowpeas were intercropped and monocropped using conventional
husbandry practices. The coccinellid were quantified based on the colonies of four coccinellids,
starved for 12 hours to enhance feeding on aphids were assessed. The effects of weather on the
abundance of coccinellids was also investigated and involved collection of meteorological data
from the Busia District Agricultural Office (BDAO) and from Busia Farmers Training Centre
(BFTC) and relating them to the abundance and predation values. The crop yield was higher in
the mixed stands of maize and beans than in pure stands by 540 kgs per acre. The predator
population was most abundant in the mixed stands of maize and beans (2.33 predators/30 aphids)
as compared to their occurrence in pure stands of cowpeas (0.85 predators/30 aphids). The genus
Cheilomenes spp was the most ubiquitous predator with a mean of 4.00 individuals/30 aphids
while Hippodamia variegate was the least abundant predator species with a mean of 0.92
individuals/ 30 aphids in all the agroecosystems. The larvae of Hippodamia variegate were the
most bio-efficient, consuming 32.44 aphids while their adults were the least bio- efficient,
consuming 4.22 individuals for a period of 12 hours. The coccinellids consumed more aphids at
higher aphid densities (24.05 aphids) than at lower aphid densities (9.44 aphids) over the same
period of time. Rainfall and relative humidity had significant (F=3.675; P<0.05) effects on the
abundance of coccinellids.Temperature had significant (F=3.58;P< 0.05) effect on the abundance
of coccinellids though at a lower level. Rainfall (r -0.162) and relative humidity (r = - 0.084)
were both inversely correlated with the abundance of coccinellids. On the other hand,
temperature was positively correlated (r=0.159) with the prevalence of coccinellids indicating
that warmer and drier conditions favoured their multiplication.
Key Words: Effectiveness, Coccinellids, Natural Enemies, Aphids, Intercrop
168 aGRO 2011 Biennial Conference IMPACT OF MANAGEMENT INTENSITY AND SHADING LEVEL ON GROWTH
AND YIELD OF COFFEE GROWN UNDER Cordia africana
1
1
Odeny, D.A., 2Chemining’wa, G.N. and 2Shibairo, S.I.
Coffee Research Foundation, P.O. Box 4-00232, Ruiru
2
Deparment of Plant Science and Crop Protection, University of Nairobi, P.O. Box 2905300625, Nairobi
Abstract (C2079)
This study was conducted to investigate the impact of management intensity and shading level of
Cordia africana on growth, clean bean yield and % grade ‘A’ beans of coffee (variety K7). The
trials were set up at the Coffee Research Foundation (CRF) demonstration farm and two
smallholder coffee farms in Namwela, Bungoma county. The three farms represented high,
medium and low management intensity treatments, respectively. The distance from the shade
tree trunk (0-2.5m, 2.5 – 5 m, 5 -7.5 m and full sun) represented different shading level
treatments. The objective was to assess the extent to which shading could be used to complement
or offset low intensity management. High management intensity coffee farm was subjected to all
agronomic practices recommended by CRF, medium intensity management farm received
minimal amounts of inputs (fertilizers and pesticides) while low management intensity farm was
not supplied with external inputs. Management intensity and shade level had significant effects
on length of primary branches, number of nodes, clean bean yield and % Grade ‘A’ beans. Clean
coffee yields were significantly higher under high management intensity than under medium and
low management intensities. Shaded coffee had significantly higher clean bean yields than
unshaded coffee under medium and low management intensities. There were no bean grade
differences among shading levels in high and low management intensities, while higher shading
levels (0-2.5 m, 2.5-5 m) ) had significantly higher % Grade ‘A’ coffee beans than unshaded
trees. These findings suggest that shading can be used to enhance coffee yields without loss in
quality, especially under smallholder low input conditions.
Key words: Shade, Cordia africana, management intensity, coffee, nodes
169 aGRO 2011 Biennial Conference EFFECT OF STEEPING AND GERMINATION PERIOD ON DIASTATIC ACTIVITY
OF AMARANTH GRAINS
Okoth Judith K, Anselimo O Makokha and Francis M. Mathooko
Agriculture and Technology, P.O. Box 62000-00200, Nairobi.
Abstract (F2118)
According to Kenya Demographic Health Survey, 7% of children under five years are wasted,
16% of them being underweight, an indication of inappropriate feeding practices. Children are
most at risk of PEM during the introduction of complementary foods usually thin porridge
prepared predominantly from cereals and starchy tubers. Such porridge is high in starch, limiting
intake due to thick consistency and the children` s small stomachs. In most cases it is diluted
with water, though infants at this stage of rapid development have high energy and nutrients
requirements per unit body weight. There is need to develop nutrient-dense complementary
foods that could be used by low income families. Amaranth grain has high biological value
proteins and a better amino acid profile than nearly all cereals. However it is not commonly used
as a complementary food in Kenya. It could give a nutrient dense complementary food with
suitable processing methods, which enhance consumption of more dry matter. This study
purposed to find out how varying steeping and germination periods affect the diastatic activity of
amaranth grains, hence the starch content. The grains were steeped for 5, 10, 15, 20 and 24 hours
respectively while germinating for 24, 48 and 72 hours. The maltose content was determined to
indicate change in starch content. A viscometer was used to measure porridge viscosity.
Ungerminated grains had the lowest diastatic activity (213 mg per 100 g dry matter), while
steeping for 10 hours and germinating for 72 hours had the highest (2225.5 mg per 100 of dry
matter). Ungerminated amaranth grains’ porridge had the highest viscosity(600 NS), while the
one from grains steeped for 5 hours and germinated for 48 hours had the lowest viscosity (<50
NS). These results show that processing reduced the starch content and the viscosity varied with
the processing time.
Keywords
Complementary foods, Starch, Processing, Maltose, Protein Energy Malnutrition
170 aGRO 2011 Biennial Conference DORMANCY CHARACTERS OF ADVANCED LATE BLIGHT TOLERANT POTATO
CLONES IN KENYA
Onditi J. O1., S.W. K Nderitu1 and J.A. Landeo2
1
Kenya Agricultural Research Institute (KARI), Tigoni P. O. Box 338-00217 Limuru
2
International Potato Centre (CIP), Sub-Saharan Africa Office Nairobi.
P.O. Box 25171, Nairobi, Kenya
Abstract (C2086)
Dormancy of potato (Solanum tuberosum L.) seed tubers is one the most important selection
characters considered by many farmers during variety evaluation and adoption. In an attempt to
identify clones with suitable dormancy characters for the Kenyan potato industry, 15 advanced
breeding clones with quantitative resistance to late blight (Phytopthora infestans Mont de Barry)
were sprouted in the diffused light store (DLS) and dark (ware) store to determine the length of
dormancy, length of sprouts and number of sprouts per tuber of each clone at 45, 60, 90,120 and
150 days after harvesting during short rains and long rains 2008 at Kenya Agricultural Research
Institute, Tigoni. Length of dormancy, length of sprouts and the number of sprouts per tuber
were significantly (P=0.05) shorter in the DLS than in the dark store. Under the recommended
DLS condition for sprouting, seed tubers of CIP 393077.54 and393382.44 had the shortest
dormancy of 45 days. Other two clones, CIP 395112.36, and 395111.13 were identified with
significant longer sprouts and at the same time higher number of sprouts per tuber than the two
checks (Tigoni and Dutch Robjin). The four clones identified will produce well sprouted tubers
for timely planting during the two cropping seasons of the year. Suitable dormancy characters in
such genotypes will also increase chances of variety adoption as well as better agronomic
performance.
Key words: Dormancy, potato, sprouts
171 aGRO 2011 Biennial Conference EFFECT OF PLANT DENSITY AND ROW WIDTH ON CANOPY ARCHITECTURE IN
SORGHUM
Otieno Susan1*, Hartmut Stützel2, Ralf Uptmoor2 Ria Duensing2
1
Kenya Agricultural Research Institute – National Potato Research Centre P. O. Box 338
Limuru, Kenya.
2
Leibniz Universität Hannover, Germany. Faculty of Natural Sciences Institute of Biological
Production Systems, Vegetable Systems Modelling. Herrenhauser Straße 2, 30419 Hannover
Germany.
Abstract
(C2093)
Plant architecture can be used to simulate resource acquisition, biomass production and plant
stand levels thus increasing for resource capture efficiencies to be compared between
architectures. In the present study five biofuel sorghum genotypes and one maize hybrid were
grown at two planting densities (20 plants/m² and 30 plants/m²) and two row widths (40 cm and
67 cm). The elevation angle, phyllotaxy and blade curvature orientation were monitored using 3
D Polhemus digitizer, while the shoot characteristics (leaf area, leaf length, leaf area index, total
biomass) were monitored by destructive measurements. Leaf area indices calculated from
destructive measurements were compared with those of nondestructive measurements using the
LAI-2000 device (Licor, Lincoln, USA). Variation of plant density caused significant changes in
architectural traits including leaf area index (LAI) and total biomass. From early stages of crop
growth, leaf elevation angle and leaf to leaf angle were markedly affected by treatments, with the
measured leaf length showing a strong correlation (r² = 0.85) to the digitized leaf length. An
interaction between plant width and population density on total biomass of the crops was
determined for one genotype (S. bicolor × S. sudanense) displaying the highest biomass and leaf
area index (LAI) under all conditions. The interactions between genotypic and environmental
characteristics affecting plant behaviour were analyzed and genotype specific characteristics for
leaf elevation angle, leaf tip angle and leaf to leaf angles were found to have no significant
difference across the different plant densities and row widths. Significant difference was detected
on the leaf length, leaf mean orientation, leaf tip angle and leaf to leaf angle across the canopy
strata of the different plant densities and row widths. One genotype gave a desirable architectural
trait which can be used as an excellent target for genetic selection to enhance yields.
Keywords: Leaf area index, biomass, genotypes, morphology
172 aGRO 2011 Biennial Conference MICROPROPAGATION OF DIFFERENT POTATO CULTIVARS IN UPSCALING
SEED POTATO PROGRAMME IN KENYA
Otieno Susan1*, Charles Lung’aho1, Miriam Mbiyu1
1
Kenya Agricultural Research Institute – National Potato Research Centre P. O. Box 338,
Limuru, Kenya.
*
Abstract (C2094)
Scarcity of good quality seed is a major constraint in potato (Solanum tuberosum) production. A
study was set out to compare the performance of liquid and solid media in potato
micropropagation using 10 potato cultivars. Sections of potato containing one node were
aseptically inoculated at 5 nodes per kilner jar for four weeks at a light intensity of 3000 lux for
16 hours photoperiod at 20° C ± 2 ° C. The Murashige and Skoog (MS) media was supplemented
with different growth regulators combinations of 0.01mg/l GA3 and 0.001mg/l kinetin. The
procedures were repeated thrice after inoculation to remove shoots from the culture vessels to
divide into sections containing several nodes which were inoculated onto fresh medium and
repeated every three weeks for three months. Results showed that there was no significant
difference between the liquid and the solid media P <0.05 regardless of the type of growth
regulators used for the parameter shoot height, root length and number of nodes. Solid media
was the best for development of complete plantlets and multiplication from meristem tips with
the plantlets having high vigour while liquid media supplemented with 0.01mg/l GA3 and
0.001mg/l kinetin was the best for sub-culturing as the plantlets had high vigour with respect to
shoot height, root length and number of nodes. Three of the 10 cultivars studied, Kenya Mpya,
Tigoni, and Asante had the highest number of nodes, shoot length and plantlet height in liquid
media as compared to Purple Gold which had low vigour (lowest number of nodes, shoot length
and plantlet height) in both liquid and solid media. There was variability of the cultivars in their
response to the micropropagation media studied suggesting that there is need to develop a
micropropagation protocol that may be suitable for most Kenyan potato cultivars.
Keywords: In vitro, micropropagation, media, Solanum tuberosum
173 aGRO 2011 Biennial Conference EVALUATION OF INSECTICIDES FOR THE MANAGEMENT OF NAVY BEAN
(Phaseolus vulgaris L.) PESTS
Rotich, D., J.H. Nderitu, Chemining’wa, G. N., Kasina, J. and F. Olubayo
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 2905300625, Nairobi
Abstract (C2096)
Pests are a major constraint to production of navy beans (Phaseolus vulgaris L.) in Kenya.
Farmers rely primarily on insecticides to control navy bean pests and use one insecticide
molecule over a long period of time, resulting in high pesticide residues and ineffective control
of aphids, beanfly, whiteflies and bean flower thrips. Therefore, a study was conducted to
determine the effect of some of the pesticides used by bean farmers on populations of aphids,
bean stem maggot and thrips, and grain yield of navy beans. The experiment was conducted in
Kimbimbi, Mwea-Tebeere, Central Kenya for two seasons in December 2009 - August 2010.
Eight pesticides namely Monceren® (imidachloprid), Gaucho® (imidachloprid), Actara®
(thiamethoxam),
Ogor®
(dimethoate),
Neembecidine®
(azadaractin),
Karate®
(lamdacyhalothrin), Cruisor® (thiamethoxam), Thunder® (imidacloprid) and a control treatment
(no pesticide was applied) were evaluated using navy bean variety Mexican 142. Total counts of
aphids, bean stem maggot and thrips were recorded and grain yield of navy beans determined.
Actara, monceren, neem and dimethoate significantly reduced the number of aphids in the first
season while cruiser, Gaucho, thunder and Karate had no effect. In the second season, Actara,
dimethoate and Karate significantly reduced the number of aphids. All the pesticides, except
neembecidine in the first season, significantly reduced the number of bean stem maggots.
Pesticides had no effect on the flower thrips in both seasons. Actara, Thunder, Ogor and Karate
significantly improved grain yield while Neembezidine, Monceren, Cruiser and Gaucho had no
effect. It is advisable for farmers to use Thunder and Actara which are environment-friendly and
have minimal residues on the seeds.
Key words: Navy bean, bean stem maggot, aphids, imidacloprid, thiamethoxam
174 aGRO 2011 Biennial Conference C2098. USE OF GGE BIPLOT METHOD TO EVALUATE STABILITY OF
PERFORMANCE OF NEW MAIZE HYBRIDS IN EASTERN AFRICA
Titus Kosgei1, Dan Makumbi2 and Kiarie Njoroge1, Brigid McDermott1
1 University of Nairobi, P. O. Box 29053- 00625, Nairobi
2 International Maize and Wheat Improvement Centre, P.O. Box 1041-00621, Nairobi
Abstract
Multi environmental trials (MET) are conducted by the International Maize and Wheat
Improvement Centre (CIMMYT) to assist in the identification of superior maize hybrids.
Information about performance of these maize hybrids may be used to target new varieties in
specific environments and also in the variety release process. Genotype main effects and
genotype x environment interaction (GGE) biplots analysis of multi-environment data provides a
unique visualization of genotype performance unlike conventional classical linear models. Forty
six three-way cross hybrids, and five commercial checks were evaluated in sixteen locations
within Eastern Africa and one location in India in the period of 2008. Our objectives were to (i)
evaluate grain yield performance of maize hybrids in individual environments and across
environments (ii) use GGE biplots analysis to investigate GE patterns for grain yield and
determine the most ideally adapted genotype, and (iii) to identify the best and most
representative test environment. Highly significant (P < 0.001) genotype, environment and
genotype x environment interactions for GY were detected. The highest yielding hybrids were
29, 31 and 22 with mean yields of 4.83, 4.75 and 4.65 tons/ha respectively across locations. GGE
biplot analysis showed that the first two principal components explained 47.13% of the GxE
interactions. Bako low nitrogen, Mparambu well watered and Embu well watered environments
were the most discriminating environments but not representative of the other environments.
Kibos and Kakamega well watered environments, both in western Kenya, were the most
representative and ideal for genotype testing. The most ideal genotypes were 29, 31 and 33 in
terms of high grain yields and stability of performance across locations. These hybrids should be
entered in National Performance Trials (NPT) for further testing and release for commercial
production.
Keywords: Maize, GGE biplot, stability, MET
175 aGRO 2011 Biennial Conference NUTRITIONAL EVALUATION OF THE SUITABILITY OF PROSOPIS PODS FOR
LIVESTOCK FEED IN KENYA
1
Wahome, R.G., Choge, S., Wamwere, N., Mnene, J., Wang’ombe, E., and Matere, J.
Abstract (A2128)
To study the suitability of prosopis pods flour as a feed ingredient in manufacture of animal
feeds, prosopis were collected from four districts heavily affected by the invasive species. Pods
were collected from trees at three levels; green but mature pods still attached to the twigs,
yellow (dry) pods still attached to the tree and yellow (dry) pods that have dropped onto the
ground from the tree. Pods picked from the ground were inspected against decay or insect
damage. These samples were analyzed at the department of animal production laboratory
University of Nairobi for proximate chemical composition, fibre composition, and calcium and
phosphorus profiles. In addition cost comparisons between prosopis pod flour and animal
feedstuffs with approximate chemical composition were done. Pods collected in Tana River and
Garissa districts were drier than those collected in Baringo indicating potentially better keeping
quality. The pods protein content averaged 11.7% but the fibre content was on the higher side at
29.8%. The calcium and phosphorus level, at 0.3% and 0.36% respectively, were considerably
higher than those found in cereals although its availability on digestion was likely to be affected
by the high fibre level. From the preliminary analysis, it was concluded that the flour will form a
valuable addition to the feed ingredient base in Kenya.
Key Words: Prosopis pods, feed quality, nutrient composition
176 aGRO 2011 Biennial Conference OCCURRENCE OF COMMON MAIZE DISEASES IN KIAMBU, EMBU AND
NAKURU COUNTIES OF KENYA
Charles, K. A1., Muiru, W. M1., Kimenju, J. W1. and Miano, D. W2.
1
Department of Plant Science and Crop Protection, Faculty of Agriculture, University of
Nairobi, P. O. Box 29053 00625, Kangemi.
2
Biotechnology Centre, Kenya Agricultural Research Institute, P. O. Box 14733 00800, Nairobi.
Abstract (C2117)
Maize is an important food crop in Kenya and is consumed by over 80% of the population.
Maize is produced in most regions of Kenya, including areas where it is not suited. A survey was
done in different agro-ecological zones in Kiambu, Embu and Nakuru counties to determine the
occurrence of northern leaf blight (NLB, Exserohilum turcicum), common rust (Puccinia sorghi),
maize streak disease (Maize streak virus, MSV), gray leaf spot (Cercospora maydis), head smut
(Sphaelotheca reiliana) and common smut (Ustilago maydis). Structured questionnaires were
used to obtain information from 13 farmers in Kiambu, 12 in Embu and and 16 in Nakuru. Data
collected included the incidence and severity of each of the diseases. The most common disease
in all the three counties was NLB with an average incidence of 90% and severity of 0.5 on a
scale 0.5 to 5, indicating very low the severity. Common rust had a high incidence of 74%, but
not very severe (average of 2 in a scale of 1 -5). MSV was present in all the counties with an
average incidence of 2% and a severity score of up to 4 on a scale of 1 to 5. The most affected
county was Kiambu, Embu and Nakuru, respectively. The incidences of GLS and head smut
were very low with averages of below 2.5%. MSV was clearly the most severe disease and
further studies on variability and reaction of different maize genotypes to the virus need to be
elucidated. Although the severity of all other diseases is low, the diseases were recorded in all
counties. There is likelihood that the status of these diseases can change to epidemic levels
especially with climate change. Further studies on epidemiology and management options are
needed.
Key words: Incidence, Maize, Occurrence, Maize diseases, Severity
177 aGRO 2011 Biennial Conference PIGEONPEA PHENOLOGY IN SUB HUMID AND SEMI ARID ENVIRONMENTS IN
KENYA
1*
Wanderi. S.W., 2M.W.K. Mburu and 3I.G. Nkonge
1
Kenya Agricultural Research Institute, P.O. Box 27, Embu.
Crop Science Department, University of Nairobi P.O. Box 29053, Nairobi.
3
Ministry of Agriculture, P.O. Box 30040, Nairobi.
2
Abstract (C2104)
Pigeonpea phenology is influenced by temperature and day length and this has adaptive value in
terms of the crops role in food security in different ecological zones. Field experiments were
conducted at sub-humid and semi-arid area between June 2001 and February 2002 to determine
the phenology of the long and medium duration pigeon pea. The experiments were laid out as
randomized complete block design replicated four times. Treatments included two long duration
erect and semi erect varieties (ICEAP-00053 and ICEAP-00040, respectively) and a medium
duration variety (ICEAP-00557). The pigeonpea varieties were sown in the University of
Nairobi, Kabete Field Station Farm (sub-humid) and Jomo Kenyatta University of Agriculture
and Technology Farm at Juja (semi-arid). The duration of key phenological stages were
monitored in the two sites. Thermal time accumulation was also calculated for all the pigeonpea
duration types in each location. The results showed that the phenological development varied
among the pigeonpea duration types and across the locations. The medium duration pigeonpea
flowered and matured earlier than long duration types in both sites. The long duration pigeonpea
varieties flowered and matured earlier at Kabete (160 and 190 days to flower and mature) than at
Thika (188 and 220 days to flower and mature) due to low temperatures hastening the
phenological development of long duration pigeonpea at Kabete. However, the medium duration
phenology was delayed at cooler Kabete relative to warmer at Thika. The long duration
pigeonpeas were twice as tall at Thika (264cm) compared to Kabete (126cm). This phenological
variation provides opportunities for variety targeting in different production environments.
Key words: Pigeonpea phenology, thermal time and plant height
178 aGRO 2011 Biennial Conference RESISTANCE OF POTATO VARIETIES TO Potato Tuber Moth (Phthorimaea
operculella Zeller)
*Were S., Olubayo, F., Nderitu, J., Kilalo, D. and Koech, A.
Department of Plant Science and Crop Protection, P.O Box 29053 Nairobi 00625
Abstract (C2107)
Potato tuber moth (Phthorimaea operculella Zeller; PTM) is a major pest of potato (Solanum
tuberosum L.) in the field and store, causing losses of up to 23-47 %. This study evaluated
varietal resistance to tuber moth in potatoes with an aim of contributing to IPM strategies for the
management of the pest. Five potato varieties were screened for natural resistance to PTM in the
field and in storage. The varieties were grown at Kari Tigoni where actively growing plants were
assessed for mines and larvae feeding in the mines. At harvest one thousand two hundred tubers
from each variety were sealed in khaki bags and stored at room temperature in a wooden store at
KARI-Tigoni. Destructive sampling was done to assess PTM damage, larvae and pupae per
sample of ten tubers. There was a significant difference in plants foliage damage in the field
during season one (p≤ 0.01) but not in season two (P≥0.083). Damage on tubers in storage for
the two seasons was significantly different (p≤0.007). Desiree had the least PTM damage both in
the field and store. Kihoro had the highest damage both in the field and storage. Yields were
significantly different (p≤0.018). Desiree had the lowest yields in the two seasons whereas
Tigoni had the highest yields in season one and Kenya Karibu had the highest yields in season
two. Desiree showed resistance to PTM but has a disadvantage in yield while Kihoro was
susceptible to PTM. This information can be used to feed into breeding programs to improve for
pest resistance which can be used as an IPM strategy for management of the pest.
Key words: Potato, Phthorimaea operculella, Solanum tuberosum, tuber moth, resistance.
179 aGRO 2011 Biennial Conference COMPARATIVE FARMER KNOWLEDGE OF LARGER GRAIN BORER AND ITS
MANAGEMENT IN SOUTH EASTERN KENYA
2
Nderitu JH and M Kasina1*
1
Kenya Agricultural Research Institute, P.O. Box 14733-00800 Nairobi
2
Mount Kenya University, P.O Box, 342-01000, Thika
Abstract (C2132)
South eastern Kenya is prone to frequent droughts and generally experiences low productivity of
crops and livestock. Post-harvest losses are serious as they reduce amount of harvested produce,
contributing to food insecurity. Maize post-harvest pests are a common and major problem in the
region. This study was done to compare folk knowledge about larger grain borer and other stored
maize pests and their management. A formal questionnaire was administered to respondents
presenting 109 households residing at Makueni, a pathway of larger grain borer (LGB) into
Kenya and in Kitui, which is off the LGB pathway. Maize samples were collected from farmer
stores and taken to the KARI NARL lab for assessment of pest infestation. The results show that
farmers could easily report the main maize pests particularly LGB and maize weevil. However,
when shown photos, some were unable to correctly identify the pest. Samples from Mwingi had
no LGB emergence four (4) months post sampling even though farmers listed the pest as the
most important. In contrast, Makueni samples had very high number of LGB emergence,
confirming the reporting by those farmers as the most important pest. The study findings show
that farmers may not be effectively managing LGB and other stored maize pests because of
wrong identification, resulting in application of wrong control measures.
Key words: storage pests, Makueni, Mwingi, pest control, Sitophilus zeamais, Sitotroga spp,
Ephestia spp
180 aGRO 2011 Biennial Conference SUBTHEME THREE
STRENGTHENING CAPACITY OF LOCAL UNIVERSITIES TO PROMOTE,
FACILITATE AND TEACH RURAL INNOVATION PROCESSES
1
Chemining’wa, G.N., 1Ambuko, J., 2Maina, J., 1Muiru, M.W. and 1Magomere, T.
1
Deparment of Plant Science & Crop Protection, University of Nairobi, P.O. Box 29053-00625,
Nairobi
2
Department of Animal Production, University of Nairobi, P.O. Box 29053-00625, Nairobi
Abstract (E3005)
Previous approaches in Agricultural Research and Development have had limited and often
unsustainable impact. This can be attributed to limited active participation by a broad range of
stakeholders necessary for effective innovation delivery systems. The Government of Kenya
recognizes the need for collective action between and within institutions to achieve sustainable
and positive impact in the agricultural sector with resulting development and change.
Agricultural faculties need to take their rightful role in bringing desired change in the agricultural
sector. However, the current capacity (knowledge, skills, mindsets, attitudes) of these faculties
to effect the desired changes is limited because of a common culture of individuals working
alone- the “lone-ranger syndrome”. This makes meaningful inter-institutional partnerships and
engagement with communities difficult to achieve. Therefore, an EDULINK supported initiative
called SUCAPRI (Strengthening University Capacity for promoting, facilitating and teaching
rural innovation processes) was initiated in 2008. The main objective of SUCAPRI is to
strengthen the capacity of local universities to participate in decentralised national agricultural
research systems, and to prepare professionals with the competencies needed to promote
agricultural innovation through collective action of multi- stakeholders. The methodology
adopted in the initiative is centered on developing change agents in participating universities
through a series of learning cycles based both on theories of learning and practical experience.
The initiave has achieved the following: built capacity of 21 academic staff from four
universities (Nairobi, Egerton, Jomo Kenyatta and Kenyatta) on personal and team skills,
communication, facilitating learning and action research; facilitated multistakeholder platforms
in mango, dairy goat and potato value chains; facilitated stakeholder engagement in curricula
development; improved intra-and inter-institutional networking among participating staff. The
major lesson learnt is that working together does not come naturally for most people and
therefore there is need for capacity building in collective action.
Key words: SUCAPRI, learning, innovation, networking, stakeholders, facilitation
181 aGRO 2011 Biennial Conference GUIDELINES TO AUTHORS (AFRICAN AGRICULTURE AND FORESTRY
JOURNAL – EAAFJ)
The scope of the Journal
The Journal accepts manuscripts in the area of agriculture, livestock, forestry and natural
resources from the Eastern and Central Africa Countries. Manuscripts submitted for publication
must be original reports of research not simultaneously submitted to or previously published in
any other scientific or technical journal and must make a significant contribution to the
advancement of scientific knowledge.
Short articles which do not qualify for publication as scientific papers but can make a significant
contribution to the advancement of scientific knowledge can be accepted for publication as
Journal Briefs. Critical review and interpretation papers are also accepted for publication subject
to the normal review process.
Manuscripts resulting from symposia/conferences having appropriate subject matter are also
considered for publication as a compilation in a single special issue of the Journal.
Symposia/Conferences organisers desiring to publish a compilation of manuscripts in the Journal
should contact the Editor-in-Chief with an outline of the overall purpose of the symposium and
reasons justifying why the manuscripts should be published as a special issue of the Journal. If
the request is accepted, then the Symposia/Conferences organisers would be required to instruct
the authors to prepare their manuscripts in the Journal’s format.
Manuscripts text
Manuscripts submitted to the Journal should be Word-processed on one side of A4 paper, double
spaced with one inch margins round the text. The recommended font is Times New Roman size
12. All accepted manuscript files are edited in Microsoft Word. Authors should, therefore,
compose their manuscripts in MS Word. Authors should avoid using word processing features
such as automated bulleting and numbering, head and subhead formatting or internal linking.
The typical sequence for a manuscript is title, abstract, introduction, materials and methods,
results, discussion, conclusions, acknowledgements, references. However, some manuscripts
may have a theory section, a few may have no materials and methods, or the results and
discussion section may be combined. If an appendix is needed, it should come before the
references.
The Journal uses a double-blind review in which the reviewers do not know the author names
and the authors do not know the reviewer names. Because of this, authors should prepare the
manuscript with no author by-line information such as names, addresses, affiliations,
182 aGRO 2011 Biennial Conference acknowledgments, etc. These should be submitted on a separate page to be added after the
manuscript has been accepted. Tables and figures should be labelled with reference to the
manuscript’s title and not the author names. Any identification in headers or footers should be
similarly anonymous.
Style
Authors should ensure that all abbreviations at first mention in the abstract or text and again in
the tables and figures are defined. Once an abbreviation is used, it should be used throughout the
entire manuscript except at the beginning of sentences.
The scientific names of genera, species and varieties should be in italics while the authority is in
roman type. For example: Spodoptera exempta Walk. The Latin binomial or trinomial and
authority must be shown for all plants, insects, pathogens and animals at first listing. For
example: “The test crop for this study was maize (Zea mays L.)”.
Both the common and chemical name of pesticides should be given when first mentioned. For
example: “Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) was most
persistent”. All soils should be identified at the series and family level or at least the Great Group
at first mention.
In all manuscripts, SI units should be used. If non SI units are used then metric equivalents
should be given at least once in parentheses. Numbers one through nine should be spell out
except when used with units. For decimal quantities less than one, a zero should be placed before
the decimal point.
The 24-h time system should be used with four digits for hours and minutes. For example: 1430
h for 2:30 pm and 0930 h for 9:30 am. Dates should be reported with the day first followed by
the month and the year last. All months with more than four letters should be abbreviated. For
example: 14 May, 2006 and 26 Sept., 2006.
Title and abstract
All manuscripts should have a good title that appropriately identifies and represents the subject
and purpose of the study or the major findings. A catchy title should be short, descriptive,
specific and should enable the readers to understand what the study was all about. In choosing
the title, the authors should use common names and avoid abbreviations. The recommended
length of the title is about 12 words.
Each manuscript must have a short factual abstract placed at the beginning of the manuscript.
The abstract should state clearly the rationale, objectives, methods, results and their meaning or
183 aGRO 2011 Biennial Conference scope of application. The abstract should be complete in itself so as to enable the reader to judge
the value of the article and whether or not to read it completely. It should also provide the
literature searcher with enough information to assess its value and to index it for later retrieval.
The abstract paragraph should not exceed 250 words for full articles and about 130-150 words or
less for short articles. The number of words limitation is necessary because abstracts are often
republished as printed in secondary abstracting services with similar word limits. Do not cite
figures, tables, or references in the abstract.
Statistical methods and validation of field results
The manuscripts should report enough details of the experimental design so that the results can
be judged for validity and the repeatability of the experiment is clearly possible i.e. the previous
experiments may serve as a basis for the design of future experiments. The methods of statistical
analysis must be adequately described, and references to statistical packages included in the text,
and listed in the references section. Appropriate means separation procedure must be employed
and explained. A statement of the number of replicates, their average value and some appropriate
measure of variability is usually important. Information such as analysis of variance tables
should only be given if they are relevant to the discussions. Comparison between means should
be made appropriately, as failure of this may result in incorrect scientific conclusions. Common
parameters used include the standard error of a difference between means (SED), or the standard
errors of the means (SE or SEM) when these vary between means. A statement of significance
level (P) attained in the differences should be included.
Field experiments that are sensitive to environmental interactions and in which the crop
environment is not rigidly controlled or monitored, such as studies on crop yield and yield
components, should be repeated over time or space, or both to demonstrate that similar results
can or cannot be obtained in another environmental regime.
Tables
All tables should be reduced to the simplest form and submitted on separate pages, numbered in
Roman numerals and titled at the top in lower case. The desired position of each table should be
clearly marked in the text. The authors are advised to use Microsoft Word table feature to
prepare the tables with defined cells.
Do not create tables by using the space bar and/or tab keys. Do not use the enter key within the
body of the table. Instead, separate data horizontally with a new row. Do not insert blank
columns or rows in the table to create extra spacing between columns and rows.
Asterisks or letters next to values indicating statistical significance should appear in the same cell
as the value, but not in an adjacent cell. The symbols *, ** and *** are always used to show
0.05, 0.01 and 0.001 probability levels respectively and should not used for any other purpose.
184 aGRO 2011 Biennial Conference Spell out abbreviations on first mention in tables even if they have already been defined in the
text. The reader should be able to understand the table content without referring back to the text.
Bold type, italic type or underlining can be used to highlight individual values in the table but
shading is not allowed. In the body of a table, only the first letter of the first word in a row
should be capitalised except for proper nouns.
Figures/illustrations
Line drawings and graphs submitted with the manuscript must be complete inclusive of all letters
and numerals in the figures themselves and in a form suitable for reproduction. They should be
drawn to a scale that will permit their reduction preferably by half or one third to an area not
exceeding 18 x 13 cm inclusive of legend. Keep relative sizes in mind when adding symbols,
letters and numbers to the figures. You can test the reduction quality on a copier.
All figures should be numbered in Arabic numerals and their desired position in the text
indicated. Legends to illustration must be typed in a separate sheet and not attached to the figures
nor incorporated in the text. Figures in accepted manuscripts are prepared for publication by
scanning printed copies of the figures. To maintain clear contrast, use line patterns instead of
shading and avoid thin, light lines. Although authors will be asked to submit an electronic file for
the review process, they should prepare all figures keeping in mind that high quality printed
copies will ultimately be required if the manuscript is accepted. Unless necessary otherwise, the
illustrations/diagrams should be in two-dimensions, not coloured, be clearly distinguishable, and
graphs/charts not exceeding 6 separate treatments/entries in one figure, in order to avoid
overcrowding and ambiguity. They should follow the order shown below.
185 aGRO 2011 Biennial Conference 1
2
3
4
5
6
1
Graphs (example)
2
3
4
5
6
Charts (example)
Observation exceeding 6 entries can be separated into e.g. Figure 1 (a) and (b) and be clearly
labelled to reflect being from the same data set. Otherwise it could be better to present large sets
of data in tables. In curves presenting experimental results the determined points should be
clearly shown. The symbols used, in order of preference should be:
, ◊, □ , ∆ ,
, x
In all cases, the error bars should be included where necessary, particularly if they can strengthen
the discussion/interpretation.
Only two photographs for reproduction as plates are allowed per manuscript. An additional
plates shall be paid for by the author. Authors should supply un-mounted glossy prints with good
contrast, numbered and marked lightly on the back with the title of the manuscript but not the
author’s name to preserve anonymity. The orientation of the picture should be indicated clearly if
there could be any doubt at all as to which way is up.
The authors should indicate in their covering letter the number of illustrations, figures etc
enclosed. The Journal has not facility for colour photographs.
References
The reference section is typically limited to published literature and unpublished but available
reports, abstracts, theses and dissertations. Authors should cite all references in the text by name
and year. For example (Brown, 1963) or (Kilewe and Mbuvi, 1988) or Brown (1963) or Kilewe
186 aGRO 2011 Biennial Conference and Mbuvi (1988) found that... References with more than two authors should be cited in the text
as follows – (Kilewe et a1., 1989) or Kilewe et. al. (1989) found that...
Only those references cited in the text should be included under the references in alphabetical
order. The references should be compiled in the alphabetical list starting with the surname of the
first author followed by the second and third authors The title of the journal should be
abbreviated as in the 4th edition of The World List of Scientific Periodicals.
For journal articles - give the authors, year, complete article title, abbreviated journal title,
volume number and inclusive pages. For books - give the authors, year, complete book title,
publisher and place of publication. For book chapters - give the authors, year, chapter title,
pages, book editors), complete book title, publisher and place of publication. For proceedings give the authors, year, article title, proceedings editors), title of the proceedings, the place and
date of the conference, publisher and place of publication and number of pages.
Proceedings
[1] Esilaba, A.O., Reda, F., Ransom, J.K., Wondimu Bayu, Gebremehdin Woldewahid and
Beyenesh Zemichael. (1999). The potential for relay cropping and improved fallows for
soil fertility improvement and Striga control in northern Ethiopia. Proceedings of the
Seventeenth Soil Science Society of East Africa Conference, 6-10 September 1999,
Kampala, Uganda. pp 54-62.
Journal article
[2] Smith, D.T., Johnson, D.L. and Thomas, J.K. (2001). Phosphorus losses in irrigation runoff.
J. Environ. Qual.30, 256-258.
Book
[3] Lindsay, W.L. (1979). Chemical equilibria in soils. John Wiley & Sons, New York.
Chapter in a book
[4] Nelson, D.W. and Sommers, L.E. (1982). Total carbon, organic carbon, and organic matter.
P. 539-579. In: Methods of soil analysis (Page, A.L., Miller, R.H. and Keeney , D.R. ed.).
Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
Chapter in a proceedings
[5] Power, F.F. and Biederbeck, V.O. (1991). Role of cover crops in integrated crop production
systems. In: Cover crops for clean water. Proc. Int. Conf., Jackson (Hargrove, W.L. ed),
TN. 9-11 Apr. 1991. Soil and Water Conserv. Soc., Ankeny, IA. P. 167-174.
187 aGRO 2011 Biennial Conference Submitting a manuscripts
Authors should send a printed copy and diskette/CD-ROM with the manuscript file to the Editorin-Chief, East African Agricultural and Forestry Journal, Kenya Agricultural Research Institute,
P.O. Box 57811 00200, Nairobi, Kenya. In addition to this the authors can also submit the
manuscript electronically vide the following Email: [email protected]. The printed copy and a
MS Word processing file submitted must match exactly in all parts of the printed copy.
The cover page that includes the title, acknowledgements, contributing institutions, brief
statement of financial support and by-line such as names of all authors with their complete
current addresses) should be separate from the manuscript. In case of electronic submission, the
cover page should be send as a separate attachment.
The corresponding author, who should be identified with an asterisk in the by-line, is the one
who shall work with the editors during review and production of the article.
The manuscripts submitted to the Journal shall not necessarily be published in order of their
receipt. Those that require little editing are likely to appear earlier. All enquiries regarding the
progress on the manuscripts should be addressed to the Editor-in-Chief.
Reprints
First authors receive 25 reprints of their papers free of charge and may purchase additional the
copies if ordered and paid for before publication. The order form is available from the Editor-inChief on request.
188

aGRO 2011 Biennial Conference BOOK OF ABSTRACTS

Transcription

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